IDEAS home Printed from https://ideas.repec.org/p/osf/osfxxx/umq8d.html
   My bibliography  Save this paper

Degrees of freedom in planning, running, analyzing, and reporting psychological studies A checklist to avoid p-hacking

Author

Listed:
  • Wicherts, Jelte M.

    (Tilburg University)

  • Veldkamp, Coosje Lisabet Sterre
  • Augusteijn, Hilde
  • Bakker, Marjan
  • van Aert, Robbie Cornelis Maria
  • van Assen, Marcel A. L. M.

Abstract

The designing, collecting, analyzing, and reporting of psychological studies entail many choices that are often arbitrary. The opportunistic use of these so-called researcher degrees of freedom aimed at obtaining statistically significant results is problematic because it enhances the chances of false positive results and may inflate effect size estimates. In this review article, we present an extensive list of 34 degrees of freedom that researchers have in formulating hypotheses, and in designing, running, analyzing, and reporting of psychological research. The list can be used in research methods education, and as a checklist to assess the quality of preregistrations and to determine the potential for bias due to (arbitrary) choices in unregistered studies.

Suggested Citation

  • Wicherts, Jelte M. & Veldkamp, Coosje Lisabet Sterre & Augusteijn, Hilde & Bakker, Marjan & van Aert, Robbie Cornelis Maria & van Assen, Marcel A. L. M., 2016. "Degrees of freedom in planning, running, analyzing, and reporting psychological studies A checklist to avoid p-hacking," OSF Preprints umq8d, Center for Open Science.
    • Handle: RePEc:osf:osfxxx:umq8d
    DOI: 10.31219/osf.io/umq8d
    as

    Download full text from publisher

    File URL: https://osf.io/download/581b31eeb83f69004ae114ff/
    Download Restriction: no
    File URL: https://libkey.io/10.31219/osf.io/umq8d?utm_source=ideas
    LibKey link: if access is restricted and if your library uses this service, LibKey will redirect you to where you can use your library subscription to access this item
    ---><---

    References listed on IDEAS

    as
    1. John P A Ioannidis, 2005. "Why Most Published Research Findings Are False," PLOS Medicine, Public Library of Science, vol. 2(8), pages 1-1, August.
    2. Jelte M Wicherts & Marjan Bakker & Dylan Molenaar, 2011. "Willingness to Share Research Data Is Related to the Strength of the Evidence and the Quality of Reporting of Statistical Results," PLOS ONE, Public Library of Science, vol. 6(11), pages 1-7, November.
    3. Sala-i-Martin, Xavier, 1997. "I Just Ran Two Million Regressions," American Economic Review, American Economic Association, vol. 87(2), pages 178-183, May.
    4. Daniel Wigboldus & Ron Dotsch, 2016. "Encourage Playing with Data and Discourage Questionable Reporting Practices," Psychometrika, Springer;The Psychometric Society, vol. 81(1), pages 27-32, March.
    Full references (including those not matched with items on IDEAS)

    Citations

    Citations are extracted by the CitEc Project, subscribe to its RSS feed for this item.
    as


    Cited by:

    1. Felix Holzmeister & Magnus Johannesson & Robert Böhm & Anna Dreber & Jürgen Huber & Michael Kirchler, 2023. "Heterogeneity in effect size estimates: Empirical evidence and practical implications," Working Papers 2023-17, Faculty of Economics and Statistics, Universität Innsbruck.
    2. repec:osf:osfxxx:gv25c_v1 is not listed on IDEAS
    3. Shaw, Steven D. & Nave, Gideon, 2023. "Don't hate the player, hate the game: Realigning incentive structures to promote robust science and better scientific practices in marketing," Journal of Business Research, Elsevier, vol. 167(C).
    4. Schweinsberg, Martin & Feldman, Michael & Staub, Nicola & van den Akker, Olmo R. & van Aert, Robbie C.M. & van Assen, Marcel A.L.M. & Liu, Yang & Althoff, Tim & Heer, Jeffrey & Kale, Alex & Mohamed, Z, 2021. "Same data, different conclusions: Radical dispersion in empirical results when independent analysts operationalize and test the same hypothesis," Organizational Behavior and Human Decision Processes, Elsevier, vol. 165(C), pages 228-249.
    5. Maximilian M Mandl & Sabine Hoffmann & Sebastian Bieringer & Anna E Jacob & Marie Kraft & Simon Lemster & Anne-Laure Boulesteix, 2024. "Raising awareness of uncertain choices in empirical data analysis: A teaching concept toward replicable research practices," PLOS Computational Biology, Public Library of Science, vol. 20(3), pages 1-10, March.
    6. Freuli, Francesca & Held, Leonhard & Heyard, Rachel, 2022. "Replication Success under Questionable Research Practices - A Simulation Study," I4R Discussion Paper Series 2, The Institute for Replication (I4R).
    7. Lisa Spitzer & Stefanie Mueller, 2023. "Registered report: Survey on attitudes and experiences regarding preregistration in psychological research," PLOS ONE, Public Library of Science, vol. 18(3), pages 1-34, March.
    8. Chin, Jason & Zeiler, Kathryn, 2021. "Replicability in Empirical Legal Research," LawRxiv 2b5k4, Center for Open Science.
    9. repec:osf:metaar:s4b65_v1 is not listed on IDEAS
    10. Adler, Susanne Jana & Sharma, Pratyush Nidhi & Radomir, Lăcrămioara, 2023. "Toward open science in PLS-SEM: Assessing the state of the art and future perspectives," Journal of Business Research, Elsevier, vol. 169(C).
    11. repec:osf:osfxxx:7dc6a_v1 is not listed on IDEAS
    12. repec:osf:metaar:2bj85_v1 is not listed on IDEAS
    13. Denise Rousseau & Byeong Jo Kim & Ryan Splenda & Sarah Young & Jangbum Lee & Donna Beck, 2023. "Does chief executive compensation predict financial performance or inaccurate financial reporting in listed companies: A systematic review," Campbell Systematic Reviews, John Wiley & Sons, vol. 19(4), December.
    14. Gabriel Nova & Sander van Cranenburgh & Stephane Hess, 2024. "Understanding the decision-making process of choice modellers," Papers 2411.01704, arXiv.org, revised Jun 2025.
    15. Freuli, Francesca & Held, Leonhard & Heyard, Rachel, 2022. "Replication success under questionable research practices – a simulation study," MetaArXiv s4b65, Center for Open Science.
    16. Daniel McNeish, 2024. "Practical Implications of Sum Scores Being Psychometrics’ Greatest Accomplishment," Psychometrika, Springer;The Psychometric Society, vol. 89(4), pages 1148-1169, December.
    17. Adler, Susanne Jana & Röseler, Lukas & Schöniger, Martina Katharina, 2023. "A toolbox to evaluate the trustworthiness of published findings," Journal of Business Research, Elsevier, vol. 167(C).
    18. repec:osf:metaar:e4pum_v1 is not listed on IDEAS
    19. Jasper Brinkerink, 2023. "When Shooting for the Stars Becomes Aiming for Asterisks: P-Hacking in Family Business Research," Entrepreneurship Theory and Practice, , vol. 47(2), pages 304-343, March.
    20. Alexander Mielke, 2023. "Impact of dominance rank specification in dyadic interaction models," PLOS ONE, Public Library of Science, vol. 18(7), pages 1-19, July.
    21. repec:osf:osfxxx:ksxwv_v1 is not listed on IDEAS
    22. Reca Sarfati & Vod Vilfort, 2025. ""Post" Pre-Analysis Plans: Valid Inference for Non-Preregistered Specifications," Papers 2510.02507, arXiv.org.
    23. Thibaut Arpinon & Romain Espinosa, 2023. "A Practical Guide to Registered Reports for Economists," Post-Print halshs-03897719, HAL.
    24. Augusteijn, Hilde Elisabeth Maria & Wicherts, Jelte M. & Sijtsma, Klaas & van Assen, Marcel A. L. M., 2023. "Quality assessment of scientific manuscripts in peer review and education," OSF Preprints 7dc6a, Center for Open Science.

    Most related items

    These are the items that most often cite the same works as this one and are cited by the same works as this one.
    1. Abel Brodeur & Mathias Lé & Marc Sangnier & Yanos Zylberberg, 2016. "Star Wars: The Empirics Strike Back," American Economic Journal: Applied Economics, American Economic Association, vol. 8(1), pages 1-32, January.
    2. Stanley, T. D. & Doucouliagos, Chris, 2019. "Practical Significance, Meta-Analysis and the Credibility of Economics," IZA Discussion Papers 12458, Institute of Labor Economics (IZA).
    3. Kraft-Todd, Gordon T. & Rand, David G., 2021. "Practice what you preach: Credibility-enhancing displays and the growth of open science," Organizational Behavior and Human Decision Processes, Elsevier, vol. 164(C), pages 1-10.
    4. Klaas Sijtsma, 2016. "Playing with Data—Or How to Discourage Questionable Research Practices and Stimulate Researchers to Do Things Right," Psychometrika, Springer;The Psychometric Society, vol. 81(1), pages 1-15, March.
    5. Dragana Radicic & Geoffrey Pugh & Hugo Hollanders & René Wintjes & Jon Fairburn, 2016. "The impact of innovation support programs on small and medium enterprises innovation in traditional manufacturing industries: An evaluation for seven European Union regions," Environment and Planning C, , vol. 34(8), pages 1425-1452, December.
    6. Bruns, Stephan B. & Ioannidis, John P.A., 2020. "Determinants of economic growth: Different time different answer?," Journal of Macroeconomics, Elsevier, vol. 63(C).
    7. Strømland, Eirik & Torsvik, Gaute, 2019. "Intuitive Prosociality: Heterogeneous Treatment Effects or False Positive?," OSF Preprints hrx2y, Center for Open Science.
    8. Klaus E Meyer & Arjen Witteloostuijn & Sjoerd Beugelsdijk, 2017. "What’s in a p? Reassessing best practices for conducting and reporting hypothesis-testing research," Journal of International Business Studies, Palgrave Macmillan;Academy of International Business, vol. 48(5), pages 535-551, July.
    9. Matteo Colombo & Georgi Duev & Michèle B Nuijten & Jan Sprenger, 2018. "Statistical reporting inconsistencies in experimental philosophy," PLOS ONE, Public Library of Science, vol. 13(4), pages 1-12, April.
    10. Stephen A. Gorman & Frank J. Fabozzi, 2021. "The ABC’s of the alternative risk premium: academic roots," Journal of Asset Management, Palgrave Macmillan, vol. 22(6), pages 405-436, October.
    11. Irwin Waldman & Scott Lilienfeld, 2016. "Thinking About Data, Research Methods, and Statistical Analyses: Commentary on Sijtsma’s (2014) “Playing with Data”," Psychometrika, Springer;The Psychometric Society, vol. 81(1), pages 16-26, March.
    12. Aguinis, Herman & Banks, George C. & Rogelberg, Steven G. & Cascio, Wayne F., 2020. "Actionable recommendations for narrowing the science-practice gap in open science," Organizational Behavior and Human Decision Processes, Elsevier, vol. 158(C), pages 27-35.
    13. Colombo, Matteo & Duev, Georgi & Nuijten, M.B. & Sprenger, Jan, 2018. "Statistical reporting inconsistencies in experimental philosophy," Other publications TiSEM 075f5696-ae1a-4aae-9e17-c, Tilburg University, School of Economics and Management.
    14. Rao, B. Bhaskara, 2010. "Estimates of the steady state growth rates for selected Asian countries with an extended Solow model," Economic Modelling, Elsevier, vol. 27(1), pages 46-53, January.
    15. Cho, Seo-young & Vadlamannati, Krishna Chaitanya, 2010. "Compliance for big brothers: An empirical analysis on the impact of the anti-trafficking protocol," University of Göttingen Working Papers in Economics 118, University of Goettingen, Department of Economics.
    16. Jeffrey Frankel, 2014. "Mauritius: African Success Story," NBER Chapters, in: African Successes, Volume IV: Sustainable Growth, pages 295-342, National Bureau of Economic Research, Inc.
    17. Valerie Cerra & Sweta Chaman Saxena, 2008. "Growth Dynamics: The Myth of Economic Recovery," American Economic Review, American Economic Association, vol. 98(1), pages 439-457, March.
    18. Mueller-Langer, Frank & Fecher, Benedikt & Harhoff, Dietmar & Wagner, Gert G., 2019. "Replication studies in economics—How many and which papers are chosen for replication, and why?," EconStor Open Access Articles and Book Chapters, ZBW - Leibniz Information Centre for Economics, vol. 48(1), pages 62-83.
    19. Roger M. Cooke & Harry Joe & Bo Chang, 2020. "Vine copula regression for observational studies," AStA Advances in Statistical Analysis, Springer;German Statistical Society, vol. 104(2), pages 141-167, June.
    20. Balima, Hippolyte Weneyam, 2020. "Coups d’état and the cost of debt," Journal of Comparative Economics, Elsevier, vol. 48(3), pages 509-528.

    More about this item

    Statistics

    Access and download statistics

    Corrections

    All material on this site has been provided by the respective publishers and authors. You can help correct errors and omissions. When requesting a correction, please mention this item's handle: RePEc:osf:osfxxx:umq8d. See general information about how to correct material in RePEc.

    If you have authored this item and are not yet registered with RePEc, we encourage you to do it here. This allows to link your profile to this item. It also allows you to accept potential citations to this item that we are uncertain about.

    If CitEc recognized a bibliographic reference but did not link an item in RePEc to it, you can help with this form .

    If you know of missing items citing this one, you can help us creating those links by adding the relevant references in the same way as above, for each refering item. If you are a registered author of this item, you may also want to check the "citations" tab in your RePEc Author Service profile, as there may be some citations waiting for confirmation.

    For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: OSF (email available below). General contact details of provider: https://osf.io/preprints/ .

    Please note that corrections may take a couple of weeks to filter through the various RePEc services.

    IDEAS is a RePEc service. RePEc uses bibliographic data supplied by the respective publishers.