Preregistration (science)

{{Short description|Scientific practice}} {{citation style|date=May 2026}} '''Preregistration''' is the practice of registering the hypotheses, methods, or analyses of a scientific study before it is conducted.<ref name="Nosek et al. (2018)" /><ref>{{Cite journal|last1=Parsons|first1=Sam|last2=Azevedo|first2=Flávio|last3=Elsherif|first3=Mahmoud M.|last4=Guay|first4=Samuel|last5=Shahim|first5=Owen N.|last6=Govaart|first6=Gisela H.|last7=Norris|first7=Emma|last8=O'Mahony|first8=Aoife|last9=Parker|first9=Adam J.|last10=Todorovic|first10=Ana|last11=Pennington|first11=Charlotte R.|date=2022-02-21|title=A community-sourced glossary of open scholarship terms|url=https://www.nature.com/articles/s41562-021-01269-4|journal=Nature Human Behaviour|volume=6 |issue=3 |language=en|pages=312–318|doi=10.1038/s41562-021-01269-4|pmid=35190714 |s2cid=247025114 |issn=2397-3374|hdl=2292/62865|hdl-access=free}}</ref> '''Clinical trial registration''' is similar, although it may not require the registration of a study's analysis protocol. Finally, [[registered report]]s include the [[peer review]] and in principle acceptance of a study protocol prior to data collection.<ref>{{Cite web|title=Registered Replication Reports|url=http://www.psychologicalscience.org/index.php/replication|access-date=2015-11-13|publisher=Association for Psychological Science}}</ref>

Preregistration has the goal to transparently evaluate the severity of [[hypothesis test]]s,<ref>{{cite journal |author1-link=Daniel Lakens |last1=Lakens |first1=Daniël |title=The value of preregistration for psychological science: A conceptual analysis |journal=Japanese Psychological Review |date=2019 |volume=62 |issue=3 |pages=221–230 |doi=10.24602/sjpr.62.3_221}}</ref> and can have a number of secondary goals (which can also be achieved without preregistering <ref name="The benefits of preregistration and">{{cite journal |last1=Lakens |first1=Daniël |last2=Mesquida |first2=Cristian |last3=Rasti |first3=Sajedeh |last4=Ditroilo |first4=Massimiliano |title=The benefits of preregistration and Registered Reports |journal=Evidence-Based Toxicology |date=31 December 2024 |volume=2 |issue=1 |article-number=2376046 |doi=10.1080/2833373X.2024.2376046}}</ref>), including (a) facilitating and documenting research plans, (b) identifying and reducing questionable research practices and researcher biases,<ref>{{Cite journal |last1=Hardwicke |first1=Tom E. |last2=Wagenmakers |first2=Eric-Jan |date=January 2023 |title=Reducing bias, increasing transparency and calibrating confidence with preregistration |url=https://www.nature.com/articles/s41562-022-01497-2 |journal=Nature Human Behaviour |language=en |volume=7 |issue=1 |pages=15–26 |doi=10.1038/s41562-022-01497-2 |pmid=36707644 |issn=2397-3374}}</ref> (c) distinguishing between confirmatory and exploratory analyses,<ref name="Wagenmakers et al. (2012)" /> and, in the case of Registered Reports, (d) facilitating results-blind peer review, and (e) reducing publication bias.<ref>{{Cite journal |last1=Chambers |first1=Christopher D. |last2=Tzavella |first2=Loukia |date=January 2022 |title=The past, present and future of Registered Reports |url=https://www.nature.com/articles/s41562-021-01193-7 |journal=Nature Human Behaviour |language=en |volume=6 |issue=1 |pages=29–42 |doi=10.1038/s41562-021-01193-7 |pmid=34782730 |issn=2397-3374}}</ref>

Although the idea of preregistration is old,<ref>{{cite journal |last1=Bakan |first1=David |title=The test of significance in psychological research. |journal=Psychological Bulletin |date=1966 |volume=66 |issue=6 |pages=423–437 |doi=10.1037/h0020412|pmid=5974619 }}</ref> the practice of preregistering studies has gained prominence to mitigate certain issues that contribute to the [[replication crisis]] in scientific studies.<ref name="Nosek et al. (2018)" /> Among others, these issues include [[publication bias]] and questionable research practices, such as [[p-hacking]] and [[HARKing]].

== Types ==

=== Standard preregistration === In the standard preregistration format, researchers prepare a research protocol document prior to conducting their research. Ideally, this document indicates the research hypotheses, sampling procedure, sample size, [[research design]], testing conditions, stimuli, measures, data coding and aggregation method, criteria for data exclusions, and statistical analyses, including potential variations on those analyses. This preregistration document is then posted on a publicly available website such as the [[Open Science Framework]] or [[AsPredicted]]. The preregistered study is then conducted, and a report of the study and its results are submitted for publication together with access to the preregistration document. This preregistration approach allows peer reviewers and subsequent readers to cross-reference the preregistration document with the published research article in order to identify the presence of any opportunistic deviations of the preregistration that reduce the severity of tests. Deviations from the preregistration are possible and common in practice, but they should be transparently reported, and the consequences for the severity of the test should be evaluated.<ref>{{cite journal |last1=Lakens |first1=Daniël |title=When and How to Deviate From a Preregistration |journal=Collabra: Psychology |date=14 May 2024 |volume=10 |issue=1 |article-number=117094 |doi=10.1525/collabra.117094}}</ref>

=== Registered reports === The registered report format requires authors to submit a description of the study methods and analyses prior to data collection.<ref>{{cite journal |last1=Chambers |first1=Christopher D. |title=Registered Reports: A new publishing initiative at Cortex |journal=Cortex |date=March 2013 |volume=49 |issue=3 |pages=609–610 |doi=10.1016/j.cortex.2012.12.016|pmid=23347556 |url=https://orca.cardiff.ac.uk/id/eprint/45177/1/Chambers_Cortex_2013b_GreenOA.pdf }}</ref><ref>{{cite journal |last1=Nosek |first1=Brian A. |last2=Lakens |first2=Daniël |title=Registered Reports: A Method to Increase the Credibility of Published Results |journal=Social Psychology |date=1 May 2014 |volume=45 |issue=3 |pages=137–141 |doi=10.1027/1864-9335/a000192|url=https://research.tue.nl/en/publications/be1a30b6-a734-4e6b-893f-f2b9da9b6b6e }}</ref> Once the theoretical introduction, method, and analysis plan has been peer reviewed (Stage 1 peer review), publication of the findings is provisionally guaranteed (in principle acceptance). The proposed study is then performed, and the research report is submitted for Stage 2 peer review. Stage 2 peer review confirms that the actual research methods are consistent with the preregistered protocol, that quality thresholds are met (e.g., manipulation checks confirm the validity of the experimental manipulation), and that the conclusions follow from the data. Because studies are accepted for publication regardless of whether the results are statistically significant Registered Reports prevent publication bias. Meta-scientific research has shown that the percentage of non-significant results in Registered Reports is substantially higher than in standard publications.<ref>{{cite journal |last1=Scheel |first1=Anne M. |last2=Schijen |first2=Mitchell R. M. J. |last3=Lakens |first3=Daniël |title=An Excess of Positive Results: Comparing the Standard Psychology Literature With Registered Reports |journal=Advances in Methods and Practices in Psychological Science |date=April 2021 |volume=4 |issue=2 |page=251524592110074 |doi=10.1177/25152459211007467}}</ref><ref>{{cite journal |last1=Allen |first1=Christopher |last2=Mehler |first2=David M. A. |title=Open science challenges, benefits and tips in early career and beyond |journal=PLOS Biology |date=1 May 2019 |volume=17 |issue=5 |article-number=e3000246 |doi=10.1371/journal.pbio.3000246|doi-access=free |pmid=31042704 |pmc=6513108 }}</ref>

=== Specialized preregistration === Preregistration can be used in relation to a variety of different research designs and methods, including:

* Adaptive preregistration<ref>{{Cite journal |last1=Gould |first1=Elliot |last2=Jones |first2=Christopher |last3=Yen |first3=Jian D. L. |last4=Fraser |first4=Hannah S. |last5=Wootton |first5=Henry |last6=Good |first6=Megan Kate |last7=Duncan |first7=David |last8=Hauser |first8=Cindy E. |last9=Wintle |first9=Bonnie C. |last10=Rumpff |first10=Libby |date=2025-08-19 |title="But I can't preregister my research": Improving the reproducibility and transparency of ecology and conservation with adaptive preregistration for model-based research |url=https://ecoevorxiv.org/repository/view/9884/ |language=en}}</ref> * [[Quantitative research]] in psychology<ref name="Bosnjak et al. (2021)">{{cite journal |last1=Bosnjak |first1=M. |last2=Fiebach |first2=C. J. |last3=Mellor |first3=D. |last4=Mueller |first4=S. |last5=O'Connor |first5=D. B. |last6=Oswald |first6=F. L. |last7=Sokol-Chang |first7=R. I. |date=2021 |title=A template for preregistration of quantitative research in psychology: Report of the Joint Psychological Societies Preregistration Task Force |url= |journal=The American Psychologist |volume=77 |issue=4 |pages=602–615 |doi=10.1037/amp0000879 |pmid=34807636 |s2cid=236655778}}</ref> * Qualitative research<ref name="Haven & Van Grootel (2019)">{{cite journal |last1=Haven |first1=T. L. |last2=Van Grootel |first2=D. L. |title=Preregistering qualitative research. |journal=Accountability in Research |date=2019 |volume=26 |issue=3 |pages=229–244 |doi=10.1080/08989621.2019.1580147 |pmid=30741570 |doi-access=free }}</ref> * Preexisting data<ref name="Mertens & Krypotos (2019)">{{cite journal |last1=Mertens |first1=G. |last2=Krypotos |first2=A. M. |title=Preregistration of analyses of preexisting data. |journal=Psychologica Belgica |date=2019 |volume=59 |issue=1 |pages=338–352 |doi=10.5334/pb.493 |pmid=31497308 |pmc=6706998 |s2cid=201844047 |doi-access=free }}</ref><ref name="Weston et al. (2019)">{{cite journal |last1=Weston |first1=S. J. |last2=Ritchie |first2=S. J. |last3=Rohrer |first3=J. M. |title=Recommendations for increasing the transparency of analysis of preexisting data sets |journal=Advances in Methods and Practices in Psychological Science |date=2019 |volume=2 |issue=3 |pages=214–227 |doi=10.1177/2515245919848684 |pmid=32190814 |pmc=7079740 |doi-access=free }}</ref><ref>{{Cite journal|last1=Akker|first1=Olmo R. van den|last2=Weston|first2=Sara|last3=Campbell|first3=Lorne|last4=Chopik|first4=Bill|last5=Damian|first5=Rodica|last6=Davis-Kean|first6=Pamela|last7=Hall|first7=Andrew|last8=Kosie|first8=Jessica|last9=Kruse|first9=Elliott|last10=Olsen|first10=Jerome|last11=Ritchie|first11=Stuart|date=2021-11-09|title=Preregistration of secondary data analysis: A template and tutorial|url=https://open.lnu.se/index.php/metapsychology/article/view/2625|journal=Meta-Psychology|language=en|volume=5|doi=10.15626/MP.2020.2625|issn=2003-2714|doi-access=free}}</ref> * Single case designs<ref>{{cite journal |last1=Johnson |first1=A. H. |last2=Cook |first2=B. G. |title=Preregistration in single-case design research. |journal=Exceptional Children |date=2019 |volume=86 |issue=1 |pages=95–112 |doi=10.1177/0014402919868529 |s2cid=204363608 |doi-access=free }}</ref> *Electroencephalogram research<ref name="Paul et al. (2021)">{{cite journal |last1=Paul |first1=M. |last2=Govaart |first2=G. H. |last3=Schettino |first3=A. |title=Making ERP research more transparent: Guidelines for preregistration |journal=International Journal of Psychophysiology |date=2021 |volume=164 |pages=52–63 |doi=10.31234/osf.io/4tgve |pmid=33676957 |doi-access=free |hdl=21.11116/0000-0008-2B30-2 |hdl-access=free }}</ref> *Experience sampling<ref name="Kirtley et al. (2019)">{{cite journal |last1=Kirtley |first1=O. J. |last2=Lafit |first2=G. |last3=Achterhof |first3=R. |last4=Hiekkaranta |first4=A. P. |last5=Myin-Germeys |first5=I. |title=Making the black box transparent: A template and tutorial for (pre-)registration of studies using experience sampling methods (ESM) |journal=PsyArXiv |date=2019 |doi=10.31234/osf.io/seyq7 |s2cid=236657420 |doi-access=free }}</ref> *[[Exploratory research]]<ref name="Dirnagl (2020)">{{cite journal |last1=Dirnagl |first1=U. |title=Preregistration of exploratory research: Learning from the golden age of discovery. |journal=PLOS Biol |date=2020 |volume=18 |issue=3 |article-number=e3000690 |doi=10.1371/journal.pbio.3000690 |pmid=32214315 |pmc=7098547 |doi-access=free }}</ref> *Animal Research<ref>{{Cite journal|last1=Bert|first1=Bettina|last2=Heinl|first2=Céline|last3=Chmielewska|first3=Justyna|last4=Schwarz|first4=Franziska|last5=Grune|first5=Barbara|last6=Hensel|first6=Andreas|last7=Greiner|first7=Matthias|last8=Schönfelder|first8=Gilbert|date=2019-10-15|title=Refining animal research: The Animal Study Registry|journal=PLOS Biology|language=en|volume=17|issue=10|article-number=e3000463|doi=10.1371/journal.pbio.3000463|issn=1545-7885|pmc=6793840|pmid=31613875 |doi-access=free }}</ref>

==Clinical trial registration== '''Clinical trial registration''' is the practice of documenting [[clinical trial]]s before they are performed in a '''clinical trials registry''' so as to combat [[publication bias]] and [[analytical bias|selective reporting]].<ref>{{cite web|url=https://www.who.int/ictrp/trial_reg/en/ |archive-url=https://web.archive.org/web/20130719022249/http://www.who.int/ictrp/trial_reg/en/ |archive-date=July 19, 2013 |title=International Clinical Trials Registry Platform (ICTRP) |website=Who.int |access-date=2017-06-23}}</ref> Registration of clinical trials is required in some countries and is increasingly being standardized.<ref>{{cite web|url=https://www.who.int/ictrp/network/bpg/en/ |archive-url=https://web.archive.org/web/20081012134219/http://www.who.int/ictrp/network/bpg/en/ |archive-date=October 12, 2008 |title=WHO | Working Group on Best Practice for Clinical Trials Registers (BPG) |website=Who.int |access-date=2017-06-23}}</ref> Some top medical journals will only publish the results of trials that have been pre-registered.<ref>{{cite web |last1=Barrett |first1=Stephen |title=Major Journals Press for Clinical Trial Registration |url=https://www.quackwatch.org/06ResearchProjects/journals.html |website=www.quackwatch.org |date=13 September 2004 |access-date=22 May 2019}}</ref>

A clinical trials registry is a platform which catalogs registered clinical trials. [[ClinicalTrials.gov]], run by the [[United States National Library of Medicine]] (NLM) was the first online registry for clinical trials, and remains the largest and most widely used. In addition to combating bias, clinical trial registries serve to increase transparency and access to clinical trials for the public. Clinical trials registries are often searchable (e.g. by disease/indication, drug, location, etc.). Trials are registered by the pharmaceutical, biotech or [[medical device]] company (Sponsor) or by the hospital or foundation which is sponsoring the study, or by another organization, such as a [[contract research organization]] (CRO) which is running the study.

There has been a push from governments and international organizations, especially since 2005, to make clinical trial information more widely available and to standardize registries and processes of registering. The [[World Health Organization]] is working toward "achieving consensus on both the minimal and the optimal operating standards for trial registration".<ref>{{cite web|url=https://www.who.int/ictrp/network/bpg/en/index.html|archive-url=https://web.archive.org/web/20080917194140/http://www.who.int/ictrp/network/bpg/en/index.html|archive-date=September 17, 2008|title=WHO - Working Group on Best Practice for Clinical Trials Registers (BPG)|website=www.who.int}}</ref>

===Creation and development=== For many years, scientists and others have worried about reporting biases such that negative or null results from initiated clinical trials may be less likely to be published than positive results, thus skewing the literature and our understanding of how well interventions work.<ref name=Dickersin>{{cite journal| last1=Dickersin| first1=K| last2=Rennie| first2=D| s2cid=10184671| date=2009| title=Registering clinical trials| journal=JAMA| volume=290| issue=4| pages=516–523| pmid=12876095| doi=10.1001/jama.290.4.516}}</ref> This worry has been international and written about for over 50 years.<ref name=Sterling>{{cite journal| last1=Sterling| first1=TD|date=1959| title=Publication decisions and their possible effects on inferences drawn from tests of significances – or vice versa| journal=J Am Stat Assoc| volume=54| issue=285| pages=30–34| doi=10.1080/01621459.1959.10501497| jstor=2282137}}</ref> One of the proposals to address this potential bias was a comprehensive register of initiated clinical trials that would inform the public which trials had been started.<ref name=Adhoc>{{cite journal| author=International Collaborative Group on Clinical Trial Registries|date=1993| title=Position paper and consensus recommendations on clinical trial registries. Ad Hoc Working Party of the International Collaborative Group on Clinical Trials Registries| journal=Clin Trials Metaanal| volume=28| issue=4–5| pages=255–266| pmid=10146333}}</ref> Ethical issues were those that seemed to interest the public most, as trialists (including those with potential commercial gain) benefited from those who enrolled in trials, but were not required to "give back," telling the public what they had learned.

Those who were particularly concerned by the [[double standard]] were systematic reviewers, those who summarize what is known from clinical trials. If the literature is skewed, then the results of a [[systematic review]] are also likely to be skewed, possibly favoring the test intervention when in fact the accumulated data do not show this, if all data were made public.

[[ClinicalTrials.gov]] was originally developed largely as a result of [[breast cancer]] consumer lobbying, which led to authorizing language in the [[FDA Modernization Act of 1997]] (Food and Drug Administration Modernization Act of 1997. Pub L No. 105-115, §113 Stat 2296), but the law provided neither funding nor a mechanism of enforcement. In addition, the law required that ClinicalTrials.gov only include trials of serious and life-threatening diseases.

Then, two events occurred in 2004 that increased public awareness of the problems of [[reporting bias]]. First, the then-New York State Attorney General [[Eliot Spitzer]] sued [[GlaxoSmithKline]] (GSK) because they had failed to reveal results from trials showing that certain antidepressants might be harmful.<ref name=Dickersin2>{{cite journal| last1=Dickersin| first1=K| last2=Rennie| first2=D| date=2012| title=The evolution of trial registries and their use to assess the clinical trial enterprise| journal=JAMA| volume=307| issue=17| pages=1861–4| pmid=22550202| doi=10.1001/jama.2012.4230}}</ref>

Shortly thereafter, the [[International Committee of Medical Journal Editors]] (ICMJE) announced that their journals would not publish reports of trials unless they had been registered. The ICMJE action was probably the most important motivator for trial registration, as investigators wanted to reserve the possibility that they could publish their results in prestigious journals, should they want to.

In 2007, the [[Food and Drug Administration Amendments Act of 2007]] (FDAAA) clarified the requirements for registration and also set penalties for non-compliance (Public Law 110-85. The Food and Drug Administration Amendments Act of 2007 [https://web.archive.org/web/20090603203611/http://www.fda.gov/RegulatoryInformation/Legislation/FederalFoodDrugandCosmeticActFDCAct/SignificantAmendmentstotheFDCAct/FoodandDrugAdministrationAmendmentsActof2007/FullTextofFDAAALaw/default.htm].

===International participation=== The [[Uniform Requirements for Manuscripts Submitted to Biomedical Journals#International Committee of Medical Journal Editors|International Committee of Medical Journal Editors]] (ICMJE) decided that from July 1, 2005 no trials will be considered for publication unless they are included on a clinical trials registry.<ref>{{cite web|url=http://www.sanctr.gov.za/|title=SANCTR > Home|website=www.sanctr.gov.za}}</ref><ref>{{cite web |url=http://www.icmje.org/faq_clinical.html |title=ICMJE: Frequently Asked Questions about Clinical Trials Registration |access-date=2010-07-23 |archive-url=https://web.archive.org/web/20100706183418/http://www.icmje.org/faq_clinical.html |archive-date=2010-07-06 }}</ref> The [[World Health Organization]] has begun the push for clinical trial registration with the initiation of the [[International Clinical Trials Registry Platform]]. There has also been action from the pharmaceutical industry, which released plans to make clinical trial data more transparent and publicly available. Released in October 2008, the revised [[Declaration of Helsinki]], states that "Every clinical trial must be registered in a publicly accessible database before recruitment of the first subject."<ref>{{Cite web |url=http://www.wma.net/en/30publications/10policies/b3/index.html |title=WMA Declaration of Helsinki - Ethical Principles for Medical Research Involving Human Subjects |access-date=2010-09-02 |archive-url=https://web.archive.org/web/20110830192613/http://www.wma.net/en/30publications/10policies/b3/index.html |archive-date=2011-08-30 }}</ref><ref>{{cite web|url=http://www.anzctr.org.au/Default.aspx|title=ANZCTR|website=www.anzctr.org.au}}</ref>

The [[World Health Organization]] maintains an international registry portal called the International Clinical Trials Registry Platform intended "to ensure that a complete view of research is accessible to all those involved in health care decision making."<ref>{{cite web|url=https://www.who.int/ictrp/en/|title=International Clinical Trials Registry Platform (ICTRP)|website=World Health Organization}}</ref><ref name= Gülmezoglu >{{cite journal| last1= Gülmezoglu | first1=AM| last2=Pang| first2=T| last3=Horton| first3=R| last4=Dickersin| first4=K| date=2005| title=WHO facilitates international collaboration in setting standards for clinical trial registration| journal=Lancet| volume=365| issue=9474| pages=1829–1831| url=http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(05)66589-0/abstract | pmid= 15924966| doi=10.1016/s0140-6736(05)66589-0| s2cid=29203085| url-access=subscription}}</ref>

Since 2007, the [[Uniform Requirements for Manuscripts Submitted to Biomedical Journals#International Committee of Medical Journal Editors|International Committee of Medical Journal Editors]] ICMJE accepts all primary registries in the WHO network in addition to clinicaltrials.gov. Clinical trial registration in other registries excluding ClinicalTrials.gov has increased irrespective of study designs since 2014.<ref name= Banno >{{cite journal| last1= Banno | first1=M| last2=Tsujimoto| first2=Y| last3=Kataoka| first3=Y|date=2019| title=Studies registered in non-ClinicalTrials.gov accounted for an increasing proportion of protocol registrations in medical research| journal=Journal of Clinical Epidemiology| volume=116| pages=106–113| pmid= 31521723| doi=10.1016/j.jclinepi.2019.09.005| s2cid=202582999}}</ref>

===Reporting compliance=== Various studies have measured the extent to which various trials are in compliance with the reporting standards of their registry.<ref>{{cite journal |last1=Anderson |first1=Monique L. |last2=Chiswell |first2=Karen |last3=Peterson |first3=Eric D. |last4=Tasneem |first4=Asba |last5=Topping |first5=James |last6=Califf |first6=Robert M. |title=Compliance with Results Reporting at ClinicalTrials.gov |journal=New England Journal of Medicine |date=12 March 2015 |volume=372 |issue=11 |pages=1031–1039 |doi=10.1056/NEJMsa1409364|pmid=25760355 |pmc=4508873 }}</ref><ref>{{cite journal |last1=DeVito |first1=Nicholas J |last2=Bacon |first2=Seb |last3=Goldacre |first3=Ben |title=Compliance with legal requirement to report clinical trial results on ClinicalTrials.gov: a cohort study |journal=The Lancet |date=February 2020 |volume=395 |issue=10221 |pages=361–369 |doi=10.1016/S0140-6736(19)33220-9|pmid=31958402 |s2cid=210704225 |url=https://ora.ox.ac.uk/objects/uuid:0427c19e-a95d-4caf-978d-90f2393f8b84 }}</ref><ref>{{cite journal |last1=Pullar |first1=T |last2=Kumar |first2=S |last3=Feely |first3=M |title=Compliance in clinical trials. |journal=Annals of the Rheumatic Diseases |date=October 1989 |volume=48 |issue=10 |pages=871–5 |doi=10.1136/ard.48.10.871 |pmid=2684057|pmc=1003898 }}</ref><ref>{{cite journal |last1=Miller |first1=Jennifer E |last2=Korn |first2=David |last3=Ross |first3=Joseph S |title=Clinical trial registration, reporting, publication and FDAAA compliance: a cross-sectional analysis and ranking of new drugs approved by the FDA in 2012 |journal=BMJ Open |date=12 November 2015 |volume=5 |issue=11 |article-number=e009758 |doi=10.1136/bmjopen-2015-009758 |doi-access=free|pmid=26563214 |pmc=4654354 }}</ref><ref>{{cite web |last1=Miseta |first1=Ed |title=As ClinicalTrialsgov Turns 10 Will We See Compliance Improve |url=https://www.clinicalleader.com/doc/as-clinicaltrials-gov-turns-will-we-see-compliance-improve-0001 |website=www.clinicalleader.com |date=9 January 2018}}</ref>

===Overview of clinical trial registries=== {{see also|List of clinical trial registries}} Worldwide, there is growing number of registries. A 2013 study<ref name=adherence>{{Cite journal | last1 = Huser | first1 = V. | last2 = Cimino | first2 = J. J. | title = Evaluating adherence to the International Committee of Medical Journal Editors' policy of mandatory, timely clinical trial registration | doi = 10.1136/amiajnl-2012-001501 | journal = Journal of the American Medical Informatics Association | year = 2013 | pmid = 23396544| pmc = 3715364| volume=20 | issue=e1 | pages=e169–74}}</ref> identified the following top five registries (numbers updated as of August 2013):

{| class="wikitable" |- | 1. || ClinicalTrials.gov || '''150,551''' |- | 2. || EU register || '''21,060''' |- | 3. || Japan registries network (JPRN) || '''12,728''' |- | 4. || ISRCTN || '''11,794''' |- | 5. || Australia and New Zealand (ANZCTR) || '''8,216''' |}

=== Overview of preclinical study registries === Similar to clinical research, preregistration can help to improve transparency and quality of research data in preclinical research.<ref>{{Cite journal|last1=Wieschowski|first1=Susanne|last2=Silva|first2=Diego S.|last3=Strech|first3=Daniel|date=2016-11-10|title=Animal Study Registries: Results from a Stakeholder Analysis on Potential Strengths, Weaknesses, Facilitators, and Barriers|journal=PLOS Biology|language=en|volume=14|issue=11|article-number=e2000391|doi=10.1371/journal.pbio.2000391|issn=1545-7885|pmc=5104355|pmid=27832101 |doi-access=free }}</ref><ref>{{Cite journal|last1=Kimmelman|first1=Jonathan|last2=Anderson|first2=James A.|date=June 2012|title=Should preclinical studies be registered?|journal=Nature Biotechnology|language=en|volume=30|issue=6|pages=488–489|doi=10.1038/nbt.2261 |pmid=22678379 |pmc=4516408 |issn=1546-1696}}</ref> In contrast to clinical research where preregistration is mandatory for vast parts it is still new in preclinical research. A large part of preclinical and basic biomedical research relies on animal experiments. The non-publication of results gained from animal experiments not only distorts the state of research by reinforcing the publication bias, it further represents an ethical issue.<ref>{{Cite journal|last1=Wieschowski|first1=Susanne|last2=Biernot|first2=Svenja|last3=Deutsch|first3=Susanne|last4=Glage|first4=Silke|last5=Bleich|first5=André|last6=Tolba|first6=René|last7=Strech|first7=Daniel|date=2019-11-26|title=Publication rates in animal research. Extent and characteristics of published and non-published animal studies followed up at two German university medical centres|journal=PLOS ONE|language=en|volume=14|issue=11|article-number=e0223758|doi=10.1371/journal.pone.0223758|issn=1932-6203|pmc=6879110|pmid=31770377|bibcode=2019PLoSO..1423758W |doi-access=free }}</ref><ref>{{Cite journal|last1=Naald|first1=Mira van der|last2=Wenker|first2=Steven|last3=Doevendans|first3=Pieter A.|last4=Wever|first4=Kimberley E.|last5=Chamuleau|first5=Steven A. J.|date=2020-08-01|title=Publication rate in preclinical research: a plea for preregistration|url=https://openscience.bmj.com/content/4/1/e100051|journal=BMJ Open Science|language=en|volume=4|issue=1|article-number=e100051|doi=10.1136/bmjos-2019-100051|pmid=35047690 |pmc=8647586 |issn=2398-8703}}</ref> Preregistration is discussed as a measure that could counteract this problem. Following registries are suited for the preregistration of preclinical studies. {| class="wikitable" |+ |1. |[[Animal Study Registry|Animalstudyregistry.org]] |- |2. |[https://aspredicted.org/ AsPredicted] |- |3. |[https://osf.io/prereg/ OSF Registry] |- |4. |[https://preclinicaltrials.eu/ Preclinicaltrials.eu] |}

== Journal support == Over 200 journals offer a registered reports option ([https://cos.io/rr/ Centre for Open Science, 2019]),<ref name="Centre for Open Science (2019)">{{cite web |last1=Centre for Open Science |title=Registered Reports: Peer review before results are known to align scientific values and practices |url=https://cos.io/rr/}}</ref> and the number of journals that are adopting registered reports is approximately doubling each year ([[doi:10.1111/ejn.14319|Chambers et al., 2019]]).<ref name="Chambers et al. (2019)">{{cite journal |last1=Chambers |first1=C. D. |last2=Forstmann |first2=B. |last3=Pruszynski |first3=J. A. |title=Science in flux: Registered Reports and beyond at the European Journal of Neuroscience |journal=European Journal of Neuroscience |date=2019 |volume=49 |issue=1 |pages=4–5 |doi=10.1111/ejn.14319 |pmid=30584679 |s2cid=58645509 |doi-access=free }}</ref>

''[[Psychological Science (journal)|Psychological Science]]'' has encouraged the preregistration of studies and the reporting of effect sizes and confidence intervals.<ref>{{Cite journal|title = Replication in Psychological Science|journal = Psychological Science|date = 2015-11-09|issn = 0956-7976|pmid = 26553013|pages = 1827–32|doi = 10.1177/0956797615616374|first = D. Stephen|last = Lindsay|volume = 26|issue = 12|doi-access = free}}</ref> The [[editor-in-chief]] also noted that the editorial staff will be asking for replication of studies with surprising findings from examinations using small sample sizes before allowing the manuscripts to be published.

''[[Nature Human Behaviour]]'' has adopted the registered report format, as it "shift[s] the emphasis from the results of research to the questions that guide the research and the methods used to answer them".<ref>{{Cite journal|last=Mellor|first=D.|year=2017|title=Promoting reproducibility with registered reports|journal=Nature Human Behaviour|volume=1|article-number=0034|doi=10.1038/s41562-016-0034|s2cid=28976450|doi-access=free}}</ref>

''[[European Journal of Personality]]'' defines this format: "In a registered report, authors create a study proposal that includes theoretical and empirical background, research questions/hypotheses, and pilot data (if available). Upon submission, this proposal will then be reviewed prior to data collection, and if accepted, the paper resulting from this peer-reviewed procedure will be published, regardless of the study outcomes."<ref>{{Cite web|url=https://www.ejp-blog.com/blog/2017/2/3/streamlined-review-and-registered-reports-coming-soon|title = Streamlined review and registered reports soon to be official at EJP| date=6 February 2018 }}</ref>

Note that only a very small proportion of academic journals in psychology and neurosciences explicitly stated that they welcome submissions of replication studies in their aim and scope or instructions to authors.<ref>{{Cite journal|last=Yeung|first=Andy W. K.|date=2017|title=Do Neuroscience Journals Accept Replications? A Survey of Literature|journal=Frontiers in Human Neuroscience|language=en|volume=11|article-number=468|doi=10.3389/fnhum.2017.00468|pmid=28979201|issn=1662-5161|pmc=5611708|doi-access=free}}</ref><ref>{{Cite journal|last1=Martin|first1=G. N.|last2=Clarke|first2=Richard M.|date=2017|title=Are Psychology Journals Anti-replication? A Snapshot of Editorial Practices|journal=Frontiers in Psychology|language=en|volume=8|doi=10.3389/fpsyg.2017.00523|pmid=28443044|issn=1664-1078|pmc=5387793|page=523|doi-access=free}}</ref> This phenomenon does not encourage the reporting or even attempt on replication studies.

Overall, the number of participating journals is increasing, as indicated by the [[Center for Open Science]], which maintains a list of journals encouraging the submission of registered reports.<ref>{{Cite web |title =Registered Reports Overview |publisher=Center for Open Science |url=https://cos.io/rr/#journals|access-date = 2018-11-28}}</ref>

== Benefits == Several articles have outlined the rationale for preregistration (e.g., [https://team1mile.com/sjpr62-3/wp-content/uploads/2020/03/Lakens_JPR623221-230.pdf Lakens, 2019]; [[doi:10.1073/pnas.1708274114|Nosek et al., 2018]]; [[doi:10.1177/1745691612463078|Wagenmakers et al., 2012]]).<ref name="Wagenmakers et al. (2012)" /><ref name="Lakens (2019)">{{cite journal |last1=Lakens |first1=D. |title=The value of preregistration for psychological science: A conceptual analysis. |journal=Japanese Psychological Review |date=2019 |volume=62 |issue=3 |pages=221–230 |url=https://team1mile.com/sjpr62-3/wp-content/uploads/2020/03/Lakens_JPR623221-230.pdf}}</ref><ref name="Nosek et al. (2018)">{{cite journal|last1=Nosek|first1=B. A.|last2=Ebersole|first2=C. R.|last3=DeHaven|first3=A. C.|last4=Mellor|first4=D. T.|date=2018|title=The preregistration revolution|journal=Proceedings of the National Academy of Sciences|volume=115|issue=11|pages=2600–2606|doi=10.1073/pnas.1708274114|pmid=29531091|pmc=5856500|bibcode=2018PNAS..115.2600N |s2cid=4639380|doi-access=free}}</ref> The primary goal of preregistration is to improve the transparency of reported hypothesis tests, which allows readers to evaluate the extent to which decisions during the data analysis were pre-planned (maintaining statistical error control) or data-driven (increasing the Type 1 or Type 2 error rate).

Meta-scientific research has revealed additional benefits. Researchers indicate preregistering a study leads to a more carefully thought through research hypothesis, experimental design, and statistical analysis.<ref>{{cite journal |last1=Toth |first1=Allison A. |last2=Banks |first2=George C. |last3=Mellor |first3=David |last4=O'Boyle |first4=Ernest H. |last5=Dickson |first5=Ashleigh |last6=Davis |first6=Daniel J. |last7=DeHaven |first7=Alex |last8=Bochantin |first8=Jaime |last9=Borns |first9=Jared |title=Study Preregistration: An Evaluation of a Method for Transparent Reporting |journal=Journal of Business and Psychology |date=1 August 2021 |volume=36 |issue=4 |pages=553–571 |doi=10.1007/s10869-020-09695-3}}</ref><ref>{{cite journal |last1=Sarafoglou |first1=Alexandra |last2=Kovacs |first2=Marton |last3=Bakos |first3=Bence |last4=Wagenmakers |first4=Eric-Jan |last5=Aczel |first5=Balazs |title=A survey on how preregistration affects the research workflow: better science but more work |journal=Royal Society Open Science |date=July 2022 |volume=9 |issue=7 |article-number=211997 |doi=10.1098/rsos.211997 |doi-access=free|pmid=35814910 |pmc=9257590 |bibcode=2022RSOS....911997S }}</ref> In addition, preregistration has been shown to encourage better learning of Open Science concepts and students felt that they understood their dissertation and it improved the clarity of the manuscript writing, promoted rigour and were more likely to avoid questionable research practices.<ref>{{Cite journal |last1=Pownall |first1=Madeleine |last2=Pennington |first2=Charlotte R. |last3=Norris |first3=Emma |last4=Juanchich |first4=Marie |last5=Smailes |first5=David |last6=Russell |first6=Sophie |last7=Gooch |first7=Debbie |last8=Evans |first8=Thomas Rhys |last9=Persson |first9=Sofia |last10=Mak |first10=Matthew H. C. |last11=Tzavella |first11=Loukia |last12=Monk |first12=Rebecca |last13=Gough |first13=Thomas |last14=Benwell |first14=Christopher S. Y. |last15=Elsherif |first15=Mahmoud |date=October 2023 |title=Evaluating the Pedagogical Effectiveness of Study Preregistration in the Undergraduate Dissertation |url=http://journals.sagepub.com/doi/10.1177/25152459231202724 |journal=Advances in Methods and Practices in Psychological Science |language=en |volume=6 |issue=4 |article-number=25152459231202724 |doi=10.1177/25152459231202724 |issn=2515-2459}}</ref><ref>{{Cite book |last=Pennington |first=Charlotte R. |title=A student's guide to open science: using the replication crisis to reform psychology |date=2023 |publisher=Open University Press |isbn=978-0-335-25116-2 |location=Maidenhead}}</ref> In addition, it becomes a tool that supervisors can use to shape students to combat any questionable research practices.<ref>{{Cite journal |last1=Krishna |first1=Anand |last2=Peter |first2=Sebastian M. |date=2018-08-30 |title=Questionable research practices in student final theses – Prevalence, attitudes, and the role of the supervisor's perceived attitudes |journal=PLOS ONE |language=en |volume=13 |issue=8 |article-number=e0203470 |doi=10.1371/journal.pone.0203470 |doi-access=free |issn=1932-6203 |pmc=6117074 |pmid=30161249|bibcode=2018PLoSO..1303470K }}</ref>

A 2024 study in the ''[[Journal of Political Economy Microeconomics|Journal of Political Economy: Microeconomics]]'' preregistration in economics journals found that preregistration reduced p-hacking and publication bias if the preregistration was accompanied by a preanalysis plan, but not if the preregistration did not specify the planned analyses.<ref>{{Cite journal |last1=Brodeur |first1=Abel |last2=Cook |first2=Nikolai M. |last3=Hartley |first3=Jonathan S. |last4=Heyes |first4=Anthony |date=2024 |title=Do Preregistration and Preanalysis Plans Reduce p -Hacking and Publication Bias? Evidence from 15,992 Test Statistics and Suggestions for Improvement |url=https://www.journals.uchicago.edu/doi/10.1086/730455 |journal=Journal of Political Economy Microeconomics |volume=2 |issue=3 |pages=527–561 |language=en |doi=10.1086/730455 |hdl=10419/281136 |issn=2832-9368|url-access=subscription }}</ref>

== Criticisms ==

=== Analytical Flexibility === Proponents of preregistration have argued that it is "a method to increase the credibility of published results" ([[doi:10.1027/1864-9335/a000192|Nosek & Lakens, 2014]]), that it "makes your science better by increasing the credibility of your results" ([https://www.cos.io/initiatives/prereg Centre for Open Science]), and that it "improves the interpretability and credibility of research findings" ([[doi:10.1073/pnas.1708274114|Nosek et al., 2018]], p. 2605).<ref name="Nosek et al. (2018)" /><ref name="Nosek & Lakens (2014)">{{cite journal |last1=Nosek |first1=B. A. |last2=Lakens |first2=D. |title=Registered reports: A method to increase the credibility of published results |journal=Social Psychology |date=2014 |volume=45 |issue=3 |pages=137–141 |doi=10.1027/1864-9335/a000192 |doi-access=free }}</ref> This argument assumes that on average non-preregistered analyses are less "credible" and/or "interpretable" than preregistered analyses because researchers may opportunistically abuse flexibility in the data analysis to reduce the severity of the tests. However, critics have argued that preregistration is not necessary to take analytical flexibility into consideration: Some hypotheses allow more analytical flexibility than others (e.g., [[doi:10.1177/23780231211024421|Auspurg & Brüderl, 2021]]),<ref>{{Cite journal |last1=Auspurg |first1=Katrin |last2=Brüderl |first2=Josef |date=2021-01-01 |title=Has the Credibility of the Social Sciences Been Credibly Destroyed? Reanalyzing the "Many Analysts, One Data Set" Project |journal=Socius |language=EN |volume=7 |article-number=23780231211024421 |doi=10.1177/23780231211024421 |issn=2378-0231}}</ref> and researchers, reviewers, and readers can take these differences into account when evaluating research conclusions ([[doi:10.1093/bjps/55.1.1|Hitchcock & Sober, 2004, p. 7]]; [[doi:10.1016/S0049-237X(08)71048-6|Lakatos, 1968, pp. 375-376]]; [[doi:10.1097/EDE.0b013e318245c05b|Lash & Vandenbroucke, 2012, pp. 185-186]]; [[doi:10.1177/1745691620966796|Szollosi & Donkin, 2021, pp. 2-3]]; [[doi:10.20982/tqmp.16.4.p376|Rubin, 2020, p. 378]]; [[doi:10.1080/09515089.2022.2113771|Rubin & Donkin, 2024, p. 2035]]).<ref>{{Cite journal |last1=Hitchcock |first1=Christopher |last2=Sober |first2=Elliott |date=March 2004 |title=Prediction Versus Accommodation and the Risk of Overfitting |url=https://www.journals.uchicago.edu/doi/10.1093/bjps/55.1.1 |journal=The British Journal for the Philosophy of Science |volume=55 |issue=1 |pages=1–34 |doi=10.1093/bjps/55.1.1 |issn=0007-0882}}</ref><ref>{{Citation |last=Lakatos |first=I. |title=Changes in the Problem of Inductive Logic* |date=1968-01-01 |series=Studies in Logic and the Foundations of Mathematics |volume=51 |pages=315–417 |editor-last=Lakatos |editor-first=Imre |chapter=Changes in the Problem of Inductive Logic |url=https://www.sciencedirect.com/science/article/pii/S0049237X08710486 |access-date=2025-09-09 |publisher=Elsevier |doi=10.1016/s0049-237x(08)71048-6 |isbn=978-0-444-53415-6 }}</ref><ref>{{Cite journal |last1=Lash |first1=Timothy L. |last2=Vandenbroucke |first2=Jan P. |date=March 2012 |title=Commentary: Should Preregistration of Epidemiologic Study Protocols Become Compulsory? Reflections and a Counterproposal |url=https://journals.lww.com/00001648-201203000-00002 |journal=Epidemiology |language=en |volume=23 |issue=2 |pages=184–188 |doi=10.1097/EDE.0b013e318245c05b |pmid=22317802 |issn=1044-3983}}</ref><ref name="Szollosi & Donkin (2019)" /><ref name="Rubin (2020)" /><ref name=":3">{{Cite journal |last1=Rubin |first1=Mark |last2=Donkin |first2=Chris |date=2024-11-16 |title=Exploratory hypothesis tests can be more compelling than confirmatory hypothesis tests |journal=Philosophical Psychology |volume=37 |issue=8 |pages=2019–2047 |doi=10.1080/09515089.2022.2113771 |issn=0951-5089}}</ref> As Popper explained, theories that allow a wider "range" of predictions in a study should be downgraded as being less "severely testable" (Popper, 2002, pp. 95, 108).<ref name=":4">{{Cite book |last=Popper |first=K. R. |title=The logic of scientific discovery. |publisher=Routledge |year=2002}}</ref> Importantly, this Popperian assessment of testability can be made in the absence of preregistration ([[doi:10.1007/s11229-025-05191-4|Rubin, 2025]]).<ref name=":5">{{Cite journal |last=Rubin |first=Mark |date=2025-08-21 |title=Preregistration does not improve the transparent evaluation of severity in Popper's philosophy of science or when deviations are allowed |journal=Synthese |language=en |volume=206 |issue=3 |article-number=111 |doi=10.1007/s11229-025-05191-4 |issn=1573-0964}}</ref>

It is also worth noting that researchers face a range of practical constraints that limit their ability to opportunistically abuse analytical flexibility. Specifically, they are constrained by analytical norms and conventions as well as the requirement to produce multiple, theoretically interesting, directionally consistent results that survive robustness checks and use conceptually consistent methods and analytical approaches across multiple studies in their research articles ([[doi:10.1177/1088868313496330|Murayama et al., 2014, pp. 108-109]]; [[doi:10.1371/journal.pone.0307999|Wegener et al., 2024]]).<ref>{{Cite journal |last1=Murayama |first1=Kou |last2=Pekrun |first2=Reinhard |last3=Fiedler |first3=Klaus |date=2014-05-01 |title=Research Practices That Can Prevent an Inflation of False-Positive Rates |journal=Personality and Social Psychology Review |language=EN |volume=18 |issue=2 |pages=107–118 |doi=10.1177/1088868313496330 |pmid=23965303 |issn=1088-8683}}</ref><ref>{{Cite journal |last1=Wegener |first1=Duane T. |last2=Pek |first2=Jolynn |last3=Fabrigar |first3=Leandre R. |date=2024-08-29 |title=Accumulating evidence across studies: Consistent methods protect against false findings produced by p-hacking |journal=PLOS ONE |language=en |volume=19 |issue=8 |article-number=e0307999 |doi=10.1371/journal.pone.0307999 |doi-access=free |issn=1932-6203 |pmc=11361653 |pmid=39208346}}</ref> However, this criticism itself has been criticized as "Authors who have raised this criticism on preregistration fail to provide any real-life examples of theories that sufficiently constrain how they can be tested, nor do they provide empirical support for their hypothesis that peers can identify systematic bias".<ref name="The benefits of preregistration and"/>

=== Circular Reasoning === [[doi:10.1073/pnas.1708274114|Nosek et al. (2018)]] argued that preregistration is important because it provides a clear distinction between predictions and postdictions (post hoc explanations).<ref name="Nosek et al. (2018)" /> Failing to make this distinction can lead to the fallacy of "circular reasoning––generating a hypothesis based on observing data, and then evaluating the validity of the hypothesis based on the same data" (Nosek et al., 2018, p. 2600). However, critics have argued that preregistration is not necessary to identify circular reasoning ([[doi:10.1080/09515089.2022.2113771|Rubin & Donkin, 2024, p. 2025]]).<ref name=":3" /> Circular reasoning can be identified by analysing the logic of the reasoning per se without needing to knowing the timing of that reasoning (Popper, 1962, p. 288; Popper, 1983, p. 133; Popper, 2002, p. 274; for examples, see [[doi:10.1038/nn.2303|Kriegeskorte et al., 2009, p. 536]]).<ref>{{Cite book |last=Popper |first=K. R. |title=Conjectures and refutations: The growth of scientific knowledge. |publisher=Routledge |year=1962}}</ref><ref>{{Cite book |last=Popper |first=K. R. |title=Realism and the aim of science: From the postscript to the logic of scientific discovery. |publisher=Routledge |year=1983}}</ref><ref name=":4" /><ref>{{Cite journal |last1=Kriegeskorte |first1=Nikolaus |last2=Simmons |first2=W. Kyle |last3=Bellgowan |first3=Patrick S. F. |last4=Baker |first4=Chris I. |date=May 2009 |title=Circular analysis in systems neuroscience: the dangers of double dipping |journal=Nature Neuroscience |language=en |volume=12 |issue=5 |pages=535–540 |doi=10.1038/nn.2303 |issn=1546-1726 |pmc=2841687 |pmid=19396166}}</ref>

=== Deterring Exploratory Analyses === Critics have noted that the idea that preregistration improves research credibility may deter researchers from undertaking non-preregistered exploratory analyses ([[doi:10.1257/jep.29.3.81|Coffman & Niederle, 2015]]; see also [[doi:10.1016/j.obhdp.2021.03.002|Collins et al., 2021, Study 1]]).<ref name="Coffman & Niederle (2015)">{{cite journal |last1=Coffman |first1=L. C. |last2=Niederle |first2=M. |title=Pre-analysis plans have limited upside, especially where replications are feasible |journal=Journal of Economic Perspectives |date=2015 |volume=29 |issue=3 |pages=81–98 |doi=10.1257/jep.29.3.81 |s2cid=18163762 |doi-access=free }}</ref><ref name="Collins et al. (2021)">{{cite journal |last1=Collins |first1=H.K. |last2=Whillans |first2=A. V. |last3=John |first3=L. K |title=Joy and rigor in behavioral science. |journal=Organizational Behavior and Human Decision Processes |year=2021 |volume=164 |pages=179–191 |doi=10.1016/j.obhdp.2021.03.002 |s2cid=234848511 }}</ref> In response, preregistration advocates have stressed that a) exploratory analyses were rarely published to begin with,<ref name=":7"/> and b) that exploratory analyses are permitted in preregistered studies, and that the results of these analyses retain some value vis-a-vis hypothesis generation rather than hypothesis testing. Preregistration merely makes the distinction between confirmatory and exploratory research clearer ([[doi:10.1073/pnas.1708274114|Nosek et al., 2018]]; [[doi:10.1027/1864-9335/a000192|Nosek & Lakens, 2014]]; [[doi:10.1177/1745691612463078|Wagenmakers et al., 2012]]).<ref name="Nosek et al. (2018)" /><ref name="Wagenmakers et al. (2012)">{{cite journal |last1=Wagenmakers |first1=E. J. |last2=Wetzels |first2=R. |last3=Borsboom |first3=D. |last4=van der Maas |first4=H. L. |last5=Kievit |first5=R. A. |title=An agenda for purely confirmatory research |journal=Perspectives on Psychological Science |date=2012 |volume=7 |issue=6 |pages=632–638 |doi=10.1177/1745691612463078 |pmid=26168122 |s2cid=5096417 }}</ref><ref name="Nosek & Lakens (2014)" /> Hence, although preregistration is supposed to reduce [[researcher degrees of freedom]] during the data analysis stage, it is also supposed to be "a plan, not a prison" ([https://www.cos.io/blog/preregistration-plan-not-prison#:~:text=Preregistration%20is%20the%20process%20of,decisions%20before%20conducting%20the%20experiment.&text=As%20you'll%20see%2C%20this,made%20to%20the%20planned%20research Dehaven, 2017]).<ref name="Dehaven (2017)">{{cite web |last1=Dehaven |first1=A. |title=Preregistration: A plan, not a prison |url=https://www.cos.io/blog/preregistration-plan-not-prison#:~:text=Preregistration%20is%20the%20process%20of,decisions%20before%20conducting%20the%20experiment.&text=As%20you'll%20see%2C%20this,made%20to%20the%20planned%20research |website=Centre for Open Science |access-date=25 September 2020}}</ref> Deviations are sometimes improvements, and should be transparently reported<ref>{{cite journal |last1=Willroth |first1=Emily C. |last2=Atherton |first2=Olivia E. |title=Best Laid Plans: A Guide to Reporting Preregistration Deviations |journal=Advances in Methods and Practices in Psychological Science |date=1 January 2024 |volume=7 |issue=1 |article-number=25152459231213802 |doi=10.1177/25152459231213802 }}</ref> so that others can evaluate the consequences of the deviation. However, critics have argued that treating preregistration as a plan, rather than a prison, blurs the distinction between confirmatory and exploratory research "because adjustable plans do not control the Type I error rate" ([[doi:10.1007/s11229-025-05191-4|Rubin, 2025, p. 19]]; see also [[doi:10.31234/osf.io/wxn58|Navarro, 2020, p. 8]]),<ref name=":5" /><ref name=":6">Navarro, D. J. (2020). Paths in strange spaces: A comment on preregistration. ''PsyArXiv''. <nowiki>https://doi.org/10.31234/osf.io/wxn58</nowiki></ref> and research becomes "exploratory" when error rates are not controlled ([[doi:10.1080/02640414.2025.2486871|Ditroilo et al., 2024, p. 1109]]).<ref name=":7" />

=== The Distinction Between Confirmatory and Exploratory Research === Critics have also argued that the distinction between confirmatory and exploratory analyses is unclear and/or irrelevant ([[doi:10.1101/2020.04.26.048306|Devezer et al., 2020]]; [[doi:10.20982/tqmp.16.4.p376|Rubin, 2020]]; [[doi:10.31234/osf.io/suzej|Szollosi & Donkin, 2019]]),.<ref name="Devezer et al. (2020)">{{cite journal |last1=Devezer |first1=B. |last2=Navarro |first2=D. J. |last3=Vandekerckhove |first3=J. |last4=Buzbas |first4=E. O. |title=The case for formal methodology in scientific reform |journal=Royal Society Open Science |date=2021 |volume=8 |issue=3 |article-number=rsos.200805 |doi=10.1098/rsos.200805 |doi-access=free |pmid=34035933 |pmc=8101540 |bibcode=2021RSOS....800805D |biorxiv=10.1101/2020.04.26.048306 }}</ref><ref name="Rubin (2020)">{{cite journal |last1=Rubin |first1=M. |title=Does preregistration improve the credibility of research findings? |date=2020 |journal=The Quantitative Methods for Psychology |volume=16 |issue=4 |pages=376–390 |doi=10.20982/tqmp.16.4.p376 | arxiv=2010.10513 |s2cid=221821323 |doi-access=free }}</ref><ref name="Szollosi & Donkin (2019)">{{cite journal |last1=Szollosi |first1=A. |last2=Donkin |first2=C. |date=2021 |title=Arrested theory development: The misguided distinction between exploratory and confirmatory research |journal=Perspectives on Psychological Science |volume=16 |issue=4 |pages=717–724 |doi=10.1177/1745691620966796 |pmid=33593151 }}</ref> However, more recent work has provided a more principled definition of 'exploratory' and 'confirmatory' by arguing that "hypothesis tests are confirmatory when their error rates are controlled, and exploratory when the error rates are not controlled."<ref name=":7">{{cite journal |last1=Ditroilo |first1=Massimiliano |last2=Mesquida |first2=Cristian |last3=Abt |first3=Grant |last4=Lakens |first4=Daniël |title=Exploratory research in sport and exercise science: Perceptions, challenges, and recommendations |journal=Journal of Sports Sciences |date=18 June 2025 |volume=43 |issue=12 |pages=1108–1120 |doi=10.1080/02640414.2025.2486871|pmid=40197233 |url=https://research.tue.nl/en/publications/bd9e62c0-1380-4313-8023-6742fbb76fa3 }}</ref> which both clarifies the distinction, and demonstrates the relevance of the distinction for preregistration. As discussed above, however, this definition implies that research should be regarded as "exploratory" when preregistration is treated as "a plan, not a prison," because adjustable plans do not control error rates ([[doi:10.31234/osf.io/wxn58|Navarro, 2020, p. 8]]; [[doi:10.1007/s11229-025-05191-4|Rubin, 2025]]).<ref name=":6" /><ref name=":5" />

=== Practical Implementation === There are also concerns about the practical implementation of preregistration. Many preregistered protocols leave plenty of room for ''p''-hacking ([[doi:10.1371/journal.pbio.3000937|Bakker et al., 2020]]; [https://psyarxiv.com/nj4es Heirene et al., 2021]; [https://www.jstage.jst.go.jp/article/sjpr/62/3/62_281/_pdf Ikeda et al., 2019]; [[doi:10.1101/2021.03.12.21253378|Singh et al., 2021]]; [[doi:10.3758/s13428-023-02277-0|Van den Akker et al., 2023]]),<ref name="Bakker et al. (2020)">{{cite journal |last1=Bakker |first1=M. |last2=Veldkamp |first2=C. L. S. |last3=van Assen |first3=M. A. L. M. |last4=Crompvoets |first4=E. A. V. |last5=Ong |first5=H. H. |last6=Nosek |first6=B. |last7=Soderberg |first7=C. K. |last8=Mellor |first8=D. |last9=Wicherts |first9=J. M. |title=Ensuring the quality and specificity of preregistrations |journal=PLOS Biol |date=2020 |volume=18 |issue=12 |article-number=e3000937 |doi=10.1371/journal.pbio.3000937 |pmid=33296358 |pmc=7725296 |doi-access=free }}</ref><ref name="Ikeda et al. (2019)">{{cite journal |last1=Ikeda |first1=A. |last2=Xu |first2=H. |last3=Fuji |first3=N. |last4=Zhu |first4=S. |last5=Yamada |first5=Y. |title=Questionable research practices following pre-registration |journal=Japanese Psychological Review |date=2019 |volume=62 |issue=3 |pages=281–295 |url=https://www.jstage.jst.go.jp/article/sjpr/62/3/62_281/_pdf}}</ref><ref name="Singh et al. (2021)" /><ref name="Heirene et al. (2021)">{{cite journal |last1=Heirene |first1=R. |last2=LaPlante |first2=D. |last3=Louderback |first3=E. R. |last4=Keen |first4=B. |last5=Bakker |first5=M. |last6=Serafimovska |first6=A. |last7=Gainsbury |first7=S. M. |title=Preregistration specificity & adherence: A review of preregistered gambling studies & cross-disciplinary comparison |journal=PsyArXiv |url=https://psyarxiv.com/nj4es |access-date=17 July 2021}}</ref><ref name=":0">{{Cite journal |last1=van den Akker |first1=Olmo R. |last2=van Assen |first2=Marcel A. L. M. |last3=Bakker |first3=Marjan |last4=Elsherif |first4=Mahmoud |last5=Wong |first5=Tsz Keung |last6=Wicherts |first6=Jelte M. |date=2023-11-10 |title=Preregistration in practice: A comparison of preregistered and non-preregistered studies in psychology |journal=Behavior Research Methods |volume=56 |issue=6 |pages=5424–5433 |language=en |doi=10.3758/s13428-023-02277-0 |issn=1554-3528|doi-access=free |pmid=37950113 |pmc=11335781 }}{{Creative Commons text attribution notice|cc=by4|from this source=yes}}</ref> and researchers rarely follow the exact research methods and analyses that they preregister ([https://ideas.repec.org/p/feb/artefa/00703.html Abrams et al., 2020]; [[doi:10.31234/osf.io/d8wex|Claesen et al., 2019]]; [https://psyarxiv.com/nj4es Heirene et al., 2021]; [[doi:10.1016/j.cortex.2025.02.008|Clayson et al., 2025]];<ref name=":2">{{Cite journal |last1=Clayson |first1=Peter E. |last2=Carbine |first2=Kaylie A. |last3=Shuford |first3=John L. |last4=McDonald |first4=Julia B. |last5=Larson |first5=Michael J. |date=2025-04-01 |title=A registered report of preregistration practices in studies of electroencephalogram (EEG) and event-related potentials (ERPs): A first look at accessibility, adherence, transparency, and selection bias |url=https://linkinghub.elsevier.com/retrieve/pii/S0010945225000577 |journal=Cortex |volume=185 |pages=253–269 |doi=10.1016/j.cortex.2025.02.008 |pmid=40107168 |issn=0010-9452|url-access=subscription }}</ref> see also [[doi:10.1111/anae.14103|Boghdadly et al., 2018]]; [[doi:10.1101/2021.03.12.21253378|Singh et al., 2021]]; [http://jamanetwork.com/article.aspx?doi=10.1001/jamaophthalmol.2019.0312 Sun et al., 2019]).<ref name="Abrams et al. (2020)">{{cite journal|last1=Abrams|first1=E.|last2=Libgober|first2=J.|last3=List|first3=J. A.|date=2020|title=Research registries: Facts, myths, and possible improvements|url=https://s3.amazonaws.com/fieldexperiments-papers2/papers/00703.pdf|journal=NBER Working Papers|volume=27250}}</ref><ref name="Claesen et al. (2019)">{{cite journal |last1=Claesen |first1=A. |last2=Gomes |first2=S. |last3=Tuerlinckx |first3=F. |last4=Vanpaemel |first4=W. |last5=Leuven |first5=K. U. |date=2019 |title=Preregistration: Comparing dream to reality |journal=Royal Society Open Science |volume=8 |issue=10 |doi=10.31234/osf.io/d8wex |pmc=8548785 |pmid=34729209 |s2cid=240688291 |doi-access=free}}</ref><ref name="Boghdadly et al. (2018)">{{cite journal |last1=Boghdadly |first1=K. El. |last2=Wiles |first2=M. D. |last3=Atton |first3=S. |last4=Bailey |first4=C. R. |title=Adherence to guidance on registration of randomised controlled trials published in Anaesthesia |journal=Anaesthesia |year=2018 |volume=73 |issue=5 |pages=556–563 |doi=10.1111/anae.14103 |pmid=29292498 |doi-access=free }}</ref><ref name="Sun et al. (2019)">{{cite journal |last1=Sun |first1=L. W. |last2=Lee |first2=D. J. |last3=Collins |first3=J. A. |last4=Carll |first4=T. C. |last5=Ramahi |first5=K. |last6=Sandy |first6=S. J. |last7=Unteriner |first7=J. G. |last8=Weinberg |first8=D. V. |title=Assessment of consistency between peer-reviewed publications and clinical trial registries |journal=JAMA Ophthalmology |date=2019 |volume=137 |issue=5 |pages=552–556 |doi=10.1001/jamaophthalmol.2019.0312 |pmid=30946427 |pmc=6512264 |doi-access=free }}</ref><ref name="Singh et al. (2021)">{{Cite medRxiv |last1=Singh |first1=B. |last2=Fairman |first2=C. M. |last3=Christensen |first3=J. F. |last4=Bolam |first4=K. A. |last5=Twomey |first5=R. |last6=Nunan |first6=D. |last7=Lahart |first7=I. M. |title=Outcome reporting bias in exercise oncology trials (OREO): A cross-sectional study |date=2021 |medrxiv=10.1101/2021.03.12.21253378}}</ref><ref name="Heirene et al. (2021)" /> In terms of credibility, pre-registered studies are only of higher quality than non-pre-registered studies if the former has a power analysis and higher sample size than the latter but other than that they do not seem to prevent ''p''-hacking and HARKing, as both the proportion of positive results and effect sizes are similar between preregistered and non-preregistered studies ([[doi:10.3758/s13428-023-02277-0|Van den Akker et al., 2023]]).<ref name=":0" /> In terms of adherence, a study of 92 EEG/ERP studies showed that only 60% of studies adhered to their preregistrations or disclosed all deviations.<ref name=":2" /> Notably, registered reports had the higher adherence rates (92%) than unreviewed preregistrations (60%). In general, around three-quarters of preregistered studies included at least one deviation ([[doi:10.1007/s11229-025-05191-4|Rubin, 2025, p. 19]]).<ref name=":5" /> Hence, in many cases, what were intended as preregistered confirmatory tests end up as unplanned exploratory tests.

Again, preregistration advocates argue that deviations from preregistered plans are acceptable as long as they are reported transparently and justified. They also point out that even vague preregistrations help to reduce [[researcher degrees of freedom]] and make any residual flexibility transparent ([[doi:10.1002/jcpy.1207|Simmons et al., 2021, p. 180]]).<ref name="Simmons et al. (2021)">{{cite journal |last1=Simmons |first1=J. P. |last2=Nelson |first2=L. D. |last3=Simonsohn |first3=U. |title=Pre-registration is a game changer. But, like random assignment, it is neither necessary nor sufficient for credible science |journal=Journal of Consumer Psychology |date=2021 |volume=31 |issue=1 |pages=177–180 |doi=10.1002/jcpy.1207 |s2cid=230629031 }}</ref> However, critics argue that it is not useful to identify or justify deviations from preregistered plans when those plans do not reflect ''high quality theory and research practice''. As [[doi:10.20982/tqmp.16.4.p376|Rubin (2020)]] explained, "we should be more interested in the rationale for the ''current'' method and analyses than in the rationale for ''historical'' changes that have led up to the current method and analyses" (pp. 378–379).<ref name="Rubin (2020)" />

In addition, pre-registering a study requires careful deliberation about the study's hypotheses, research design and statistical analyses. This depends on the use of pre-registration templates that provides detailed guidance on what to include and why ([[doi:10.31222/osf.io/epgjd|Bowman et al., 2016]]; [[doi:10.1080/08989621.2019.1580147|Haven & Van Grootel, 2019]]; [[doi:10.15626/MP.2020.2625|Van den Akker et al., 2021]]).<ref>{{Cite journal |url=https://osf.io/epgjd/ |access-date=2023-11-12 |website=osf.io |doi=10.31222/osf.io/epgjd |last1=Bowman |first1=Sara D. |last2=Dehaven |first2=Alexander Carl |last3=Errington |first3=Timothy M. |last4=Hardwicke |first4=Tom Elis |last5=Mellor |first5=David Thomas |last6=Nosek |first6=Brian A. |last7=Soderberg |first7=Courtney K. |title=OSF |s2cid=242644091 }}</ref><ref>{{Cite journal |last1=L. Haven |first1=Tamarinde |last2=Van Grootel |first2=Dr. Leonie |date=2019-04-03 |title=Preregistering qualitative research |journal=Accountability in Research |language=en |volume=26 |issue=3 |pages=229–244 |doi=10.1080/08989621.2019.1580147 |issn=0898-9621|doi-access=free |pmid=30741570 }}</ref><ref>{{Cite journal |last1=Akker |first1=Olmo R. van den |last2=Weston |first2=Sara |last3=Campbell |first3=Lorne |last4=Chopik |first4=Bill |last5=Damian |first5=Rodica |last6=Davis-Kean |first6=Pamela |last7=Hall |first7=Andrew |last8=Kosie |first8=Jessica |last9=Kruse |first9=Elliott |last10=Olsen |first10=Jerome |last11=Ritchie |first11=Stuart |last12=Valentine |first12=K. D. |last13=Veer |first13=Anna van 't |last14=Bakker |first14=Marjan |date=2021-11-09 |title=Preregistration of secondary data analysis: A template and tutorial |url=https://open.lnu.se/index.php/metapsychology/article/view/2625 |journal=Meta-Psychology |language=en |volume=5 |doi=10.15626/MP.2020.2625 |issn=2003-2714|doi-access=free }}</ref> Many pre-registration template stress the importance of a power analysis but not only stress the importance of why the methodology was used.

Finally, there are concerns about the additional workload involved in preregistering studies. It takes time for researchers to prepare preregistrations ([[doi:10.36850/mr5|Hostler, 2023]]),<ref>{{Cite journal |last=Hostler |first=Thomas J. |date=2024-05-24 |title=The Invisible Workload of Open Research |url=https://journal.trialanderror.org/pub/the-invisible-workload/release/1 |journal=Journal of Trial & Error |language=en |volume=4 |issue=1 |pages=21–36 |doi=10.36850/mr5 |issn=2667-1204}}</ref> and it takes time for reviewers to cross-reference preregistrations with final research reports to identify any unreported deviations. Indeed, there is evidence that editors and reviewers do not check preregistrations during the review process ([[doi:10.36850/e5ce-4cc5|Syed, 2025]]).<ref>{{Cite journal |last=Syed |first=Moin |date=2025-04-01 |title=Some data indicating that editors and reviewers do not check preregistrations during the review process |url=https://journal.trialanderror.org/pub/check-preregistrations/release/2 |journal=Journal of Trial and Error |volume=6 |pages=8–19 |language=en |doi=10.36850/e5ce-4cc5}}</ref>

=== Qualitative Research === Critics have also argued that preregistration is less applicable, or even unsuitable, for qualitative research.<ref>{{Cite journal |last1=Fischer |first1=Eileen |last2=Guzel |first2=Gulay Taltekin |date=January 2023 |title=The case for qualitative research |url=https://myscp.onlinelibrary.wiley.com/doi/10.1002/jcpy.1300 |journal=Journal of Consumer Psychology |language=en |volume=33 |issue=1 |pages=259–272 |doi=10.1002/jcpy.1300 |issn=1057-7408|url-access=subscription }}</ref> Pre-registration imposes rigidity, limiting researchers' ability to adapt to emerging data and evolving contexts, which are essential to capturing the richness of participants' lived experiences ([[doi:10.1016/j.tourman.2024.105061|Souza-Neto & Moyle, 2025]]).<ref name=":1">{{Cite journal |last1=Souza-Neto |first1=Valério |last2=Moyle |first2=Brent |date=2025-04-01 |title=Preregistration is not a panacea, but why? A rejoinder to Chen & Li's (2024) "infusing preregistration into tourism research" |journal=Tourism Management |volume=107 |article-number=105061 |doi=10.1016/j.tourman.2024.105061 |issn=0261-5177|doi-access=free }}</ref> Additionally, it conflicts with the inductive and flexible nature of theory-building in qualitative research, constraining the exploratory approach that is central to this methodology ([[doi:10.1016/j.tourman.2024.105061|Souza-Neto & Moyle, 2025]]).<ref name=":1" />

=== Detrimental Effects === Some commentators have argued that, under some circumstances, preregistration may actually harm science by providing a false sense of credibility to research studies and analyses ([[doi:10.1101/2020.04.26.048306|Devezer et al., 2020]]; [[doi:10.31234/osf.io/cj5mh|McPhetres, 2020]]; [[doi:10.1002/jcpy.1209|Pham & Oh, 2020]]; Rubin & Donkin, 2024; [[doi:10.1016/j.tics.2019.11.009|Szollosi et al., 2020]]).<ref name="Devezer et al. (2020)" /><ref name="McPhetres (2020)">{{cite journal |last1=McPhetres |first1=J. |title=What should a preregistration contain? |date=2020 |doi=10.31234/osf.io/cj5mh |s2cid=236855127 }}</ref><ref name="Szollosi et al. (2020)">{{cite journal |last1=Szollosi |first1=A. |last2=Kellen |first2=D. |last3=Navarro |first3=D. J. |last4=Shiffrin |first4=R. |last5=van Rooji |first5=I. |last6=Van Zandt |first6=T. |last7=Donkin |first7=C. |date=2020 |title=Is preregistration worthwhile? |journal=Trends in Cognitive Sciences |volume=24 |issue=2 |pages=94–95 |doi=10.1016/j.tics.2019.11.009 |hdl=1959.4/unsworks_64138 |pmid=31892461 |s2cid=209500379}}</ref><ref name="Pham & Oh (2020)">{{cite journal |last1=Pham |first1=M. T. |last2=Oh |first2=T. T. |title=Preregistration is neither sufficient nor necessary for good science |journal=Journal of Consumer Psychology |date=2020 |volume=31 |pages=163–176 |doi=10.1002/jcpy.1209 |doi-access=free }}</ref><ref name=":3" /> Consistent with this view, there is some evidence that researchers view registered reports as being more credible than standard reports on a range of dimensions ([https://osf.io/preprints/metaarxiv/7x9vy Soderberg et al., 2020]; see also [https://dx.doi.org/10.1098/rsos.181351 Field et al., 2020] for inconclusive evidence),<ref name="Field et al. (2020)">{{cite journal |last1=Field |first1=S. M. |last2=Wagenmakers |first2=E. J. |last3=Kiers |first3=H. A. |last4=Hoekstra |first4=R. |last5=Ernst |first5=A.F. |last6=van Ravenzwaaij |first6=D. |title=The effect of preregistration on trust in empirical research findings: Results of a registered report |journal=Royal Society Open Science |date=2020 |volume=7 |issue=4 |article-number=181351 |doi=10.1098/rsos.181351 |pmid=32431853 |pmc=7211853 |bibcode=2020RSOS....781351F |doi-access=free }}</ref><ref name="Soderberg et al. (2020)">{{cite journal | last1=Soderberg | first1=Courtney K. | last2=Errington | first2=Timothy M. | last3=Schiavone | first3=Sarah R. | last4=Bottesini | first4=Julia | last5=Thorn | first5=Felix Singleton | last6=Vazire | first6=Simine | last7=Esterling | first7=Kevin M. | last8=Nosek | first8=Brian A. | title=Initial evidence of research quality of registered reports compared with the standard publishing model | journal=Nature Human Behaviour | date=2021 | volume=5 | issue=8 | pages=990–997 | doi=10.1038/s41562-021-01142-4 | pmid=34168323 | url=https://doi.org/10.1038/s41562-021-01142-4 }}</ref> although it is unclear whether this represents a "false" sense of credibility due to pre-existing positive community attitudes about preregistration or a genuine causal effect of registered reports on quality of research.

== See also == * [[AllTrials]] * [[Clinical trial registration]] * [[Metascience]] * [[Open science]]

== References ==

== External links == {{subject bar|auto=y|d=y}} * [https://www.cos.io/initiatives/prereg Preregistration resources from the Centre for Open Science] * [https://cos.io/rr/ Guidelines for creating registered reports by the Center for Open Science]

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[[Category:Peer review]] [[Category:Research]] [[Category:Metascience]] [[Category:Open science]] [[Category:Evidence-based practices]]