The Statistics Debate

October 15, 2020: Noon – 2 pm ET
(17-19:00 London Time)

(Online webinar debate, free but must register to attend on website above)


Debate Host: Dan Jeske (University of California, Riverside)

Jim Berger (Duke University)
Deborah Mayo (Virginia Tech)
David Trafimow (New Mexico State University)

Where do you stand?

  • Given the issues surrounding the misuses and abuse of p-values, do you think p-values should be used?
  • Do you think the use of estimation and confidence intervals eliminates the need for hypothesis tests?
  • Bayes Factors – are you for or against?
  • How should we address the reproducibility crisis?

If you are intrigued by these questions and have an interest in how these questions might be answered – one way of the other – then this is the event for you!

Want to get a sense of the thinking behind the practicality (or not) of various statistical approaches?  Interested in hearing both sides of the story – during the same session!?

This event will be held in a debate type of format. The participants will be given selected questions ahead of time, so they have a chance to think about their responses, but this is intended to be much less of a presentation and more of a give and take between the debaters.

So – let’s have fun with this!  The best way to find out what happens is to register and attend!

September 24: Bayes factors from all sides: who’s worried, who’s not, and why (R. Morey)

The second meeting of our New Phil Stat Forum*:

The Statistics Wars
and Their Casualties

September 24: 15:00 – 16:45  (London time)
10-11:45 am (New York, EDT) 

“Bayes Factors from all sides:
who’s worried, who’s not, and why”

Richard Morey


Richard Morey is a Senior Lecturer in the School of Psychology at the Cardiff University. In 2008, he earned a PhD in Cognition and Neuroscience and a Masters degree in Statistics from the University of Missouri. He is the author of over 50 articles and book chapters, and in 2011 he was awarded the Netherlands Research Organization Veni Research Talent grant Innovational Research Incentives Scheme grant for work in cognitive psychology. His work spans cognitive science, where he develops and critiques statistical models of cognitive phenomena; statistics, where he is interested in the philosophy of statistical inference and the development of new statistical tools for research use; and the practical side of science, where he is interested in increasing openness in scientific methodology. Morey is the author of the BayesFactor software for Bayesian inference and writes regularly on methodological topics at his blog.


R. Morey: Should we Redefine Statistical Significance

Relevant background readings for this meeting covered in the initial LSE 500 Phil Stat Seminar can be found on the Meeting #4 blogpost 
     SIST: Excursion 4 Tour II    Megateam: Redefine Statistical Significance: 

Information and directions for joining our forum are here..

Slides and Video Links:

Morey’s slides “Bayes Factors from all sides: who’s worried, who’s not, and why” are at this link:

Video Link to Morey Presentation:

Video Link to Discussion of Morey Presentation:

Mayo’s Memos: Any info or events that arise that seem relevant to share with y’all before the meeting.

*Meeting 9 of our the general Phil Stat series which began with the LSE Seminar PH500 on May 21

August 20 (meeting 8) of Phil Stat Seminar : Preregistration as a Tool to Evaluate Severity (D. Lakens)


We begin our new Phil Stat forum:

The Statistics Wars
and Their Casualties

August 20: The time is 15:00 – 16:45  (London) 10-11:45 am (New York) EDT

“Preregistration as a Tool to Evaluate
the Severity of a Test”

Daniël Lakens

Eindhoven University of Technology

Reading (by Lakens)

“The value of preregistration for psychological science: A conceptual analysis”, Japanese Psychological Review 62(3), 221–230, (2019).

Optional editorial: “Pandemic researchers — recruit your own best critics”, Nature 581, p. 121, (2020).

Information and directions for joining our forum are here.


Prof. D. Lakens’ slides (PDF)


VIDEO LINKS (3 parts):
(Viewing in full screen mode helps with buffering issues.)

Part 1: Mayo’s Introduction & Lakens’ presentation
Part 2: Lakens’ presentation continued
Part 3: Discussion


New Phil Stat Forum

The Statistics Wars
and Their Casualties

(New Date: April 4-5, 2022*) is now a monthly remote forum** 

*London School of Economics (CPNSS)

Yoav Benjamini (Tel Aviv University), Alexander Bird (University of Cambridge),
Mark Burgman (Imperial College London), Daniele Fanelli (London School of Economics and Political Science), Roman Frigg (London School of Economics and Political Science), Stephen Guettinger (London School of Economics and Political Science), David Hand (Imperial College London), Margherita Harris* (London School of Economics and Political Science), Christian Hennig (University of Bologna), Katrin Hohl (City University London), Daniël Lakens (Eindhoven University of Technology), Deborah Mayo (Virginia Tech), Richard Morey (Cardiff University), Stephen Senn (Edinburgh, Scotland), Jon Williamson (University of Kent)

*Panel Leader

While the field of statistics has a long history of passionate foundational controversy the last decade has, in many ways, been the most dramatic. Misuses of statistics, biasing selection effects, and high powered methods of Big-Data analysis, have helped to make it easy to find impressive-looking but spurious, results that fail to replicate. As the crisis of replication has spread beyond psychology and social sciences to biomedicine, genomics and other fields, people are getting serious about reforms.  Many are welcome (preregistration, transparency about data, eschewing mechanical uses of statistics); some are quite radical. The experts do not agree on how to restore scientific integrity, and these disagreements reflect philosophical battles–old and new– about the nature of inductive-statistical inference and the roles of probability in statistical inference and modeling. These philosophical issues simmer below the surface in competing views about the causes of problems and potential remedies. If statistical consumers are unaware of assumptions behind rival evidence-policy reforms, they cannot scrutinize the consequences that affect them (in personalized medicine, psychology, law, and so on). Critically reflecting on proposed reforms and changing standards requires insights from statisticians, philosophers of science, psychologists, journal editors, economists and practitioners from across the natural and social sciences. This workshop will bring together these interdisciplinary insights–from speakers as well as attendees.

Workshop OrganizersD. Mayo and R. Frigg

Logistician (chief logistics and contact person): Jean Miller 

**FORUM: This will be both a continuation of our LSEPH500 Seminar and a link to our delayed (but future) workshop. For information about how to join, see this pdf

For an explanation about the meaning of statistical crises and their casualties see here.

Past & Future Meetings:

[For information about how to join, see this pdf]

June 25, 2020 (LSE PH500 Bonus Meeting/Phil Stat Wars forum): Professor David Hand (Imperial College, London (mini-bio)) “Trustworthiness of Statistical Analysis”. (Abstract; For slides, recording & readings from this meeting, see this post.)

August 20, 2020 (15:00-16:45 (London); 10-11:45 a.m. (New York) EDT): Professor Daniël Lakens (Eindhoven University of Technology (mini-bio)) “Preregistration as a Tool to Evaluate the Severity of a Test”. (For slides, recording & readings from this meeting, see this post.)

September 24, 2020 (15:00-16:45 (London); 10-11:45 a.m. (New York) EDT):  Professor Richard Morey (Cardiff University (mini-bio)). “Bayes factors from all sides: who’s worried, who’s not, and why”. (For slides, recording & readings from this meeting, see this post.)

October 15, 2020. Statistics (P-value) Debate. Sponsored by the National Institute of Statistical Science: (For a recording, see this article.)

November 19, 2020 (15:00-16:45 (London); 10-11:45 a.m. (New York) EDT): Stephen Senn (Statistical Consultant, Scotland (mini-bio)).“Randomisation and control in the age of coronavirus?” (Abstract; For slides, recording & readings from this meeting, see this post.)

January 7, 2021 (16:00-17:30 (London); 11-12:30 (New York) EDT): D. Mayo (Philosophy, Virginia Tech (mini-bio)) “Putting the Brakes on the Breakthrough, or ‘How I used simple logic to uncover a flaw in a controversial 60-year old “theorem” in statistical foundations’”. (Abstract); (For slides, recording & readings from this meeting, see this post).

January 28, 2021 (15:00-16:45 (London); 10-11:45 a.m. (New York) EDT):Alexander Bird (Dept. of Philosophy,  University of Cambridge (mini-bio)). “How can we improve replicability?” (For slides, recording & readings from this meeting, see this post.)

February 18, 2021(15:00-16:45 (London); 10-11:45 a.m. (New York) EDT): Christian Hennig (Dept. of Statistics, University of Bologna (mini-bio)). “Testing with Models that are Not True”. (For slides, recording & readings from this meeting, see this post.)

March 25, 2021 (15:00-16:45 (London); 10-11:45 a.m. (New York) EDT): Mark Burgman (Centre for Environmental Policy, Imperial College London (mini-bio)). “How should applied science journal editors deal with statistical controversies?” (For slides, recording & readings from this meeting, see this post.)

April 22, 2021 (15:00-16:45 (London); 10-11:45 a.m. (New York) EDT): Daniele Fanelli (Dept. of Methodology, LSE (mini-bio)). “How an information metric could bring truce to the statistics wars”.  (For a recording & readings from this meeting, see this post.)

May 20, 2021 (15:00-16:45 (London); 10-11:45 a.m. (New York) EDT): Jon Williamson (Centre for Reasoning, University of Kent (mini-bio)). “Objective Bayesianism from a philosophical perspective”. (For slides, recording & readings from this meeting, see this post.)


June 24, 2021 (15:00-16:45 (London); 10-11:45 a.m. (New York) EDT): Katrin Hohl (Department of Sociology, City University London (mini-bio)). (For a recording & readings from this meeting, see this post.)

Meeting 7 (July 30)–Discussion of JSM 2020 Panel on P-values & “Statistical Significance”

All: On July 30 (10am EST) I will give a virtual version of my JSM presentation, remotely like the one I will actually give on Aug 6 at the JSM. Co-panelist Stan Young may as well. One of our surprise guests tomorrow (not at the JSM) will be Yoav Benjamini!  If you’re interested in attending our July 30 practice session* please follow the directions here. Background items for this session are in the “readings” and “memos” of session 5.

Members: Materials resulting from Meeting 7:

“Work of renowned UK psychologist Hans Eysenck ruled ‘unsafe’”, The Guardian (Oct 11, 2019) (LINK).

*unless you’re already on our LSE Phil500 list

JSM 2020 Panel Flyer (PDF)
JSM online program w/panel abstract & information):

Slides & Video Links for Meeting 7:




Meeting 6 (June 25)

VI. (June 25) BONUS MEETING: Power, shpower, severity, positive predictive value (diagnostic model) & a Continuation of The Statistics Wars and Their Casualties

There will also be a guest speaker: Professor David Hand:
      “Trustworthiness of Statistical Analysis”


SIST Excursion 5 Tour I (pp. 323-332; 338-344; 346-352),Tour II (pp. 353-6; 361-370), and Farewell Keepsake pp. 436-444

Recommended (if time) What Ever Happened to Bayesian Foundations (Excursion 6 Tour I)

Mayo Memos for Meeting 6:

-Souvenirs Meeting 6: W: The Severity Interpretation of Negative Results (SIN) for Test T+; X: Power and Severity Analysis; Z: Understanding Tribal Warfare

-JSM session I am part of on August 6: P-Values and “Statistical Significance”: Deconstructing the Arguments — Topic Contributed Panel

Nature paper just came out on which I’m a co-author: “Five Ways to Ensure Models Serve Society”

-SEV apps: Richard Morey. Newly updated Richard Morey SEV app.

-Selected blogposts on Power

  • 05/08/17: How to tell what’s true about power if you’re practicing within the error-statistical tribe
  • 12/12/17: How to avoid making mountains out of molehills (using power and severity)

Slides & Video Links for Meeting 6:

Slides: Mayo 2nd Draft slides for 25 June (not beautiful)

Video of Meeting #6: (Viewing Videos in full screen mode helps with buffering issues.)

VIDEO LINK to David Hand’s Presentation:
David Hand’s recorded Powerpoint slides:
AUDIO LINK to David Hand’s Presentation & Discussion:

Another link is here.


Meeting 5 (June 18)


V. (June 18) The Statistics Wars and Their Casualties


SIST: Excursion 4 Tour III: pp. 267-286; Farewell Keepsake pp. 436-444

-Amrhein, V., Greenland, S., & McShane, B., (2019). Comment: Retire Statistical Significance, Nature, 567: 305-308.

-Ioannidis J. (2019). “The Importance of Predefined Rules and Prespecified Statistical Analyses: Do Not Abandon Significance.” JAMA. 321(21): 2067–2068. doi:10.1001/jama.2019.4582

-Mayo, DG. (2019), P‐value thresholds: Forfeit at your peril. Eur J Clin Invest, 49: e13170. doi: 10.1111/eci.13170

Recommended (and fun) P-values on Trial: Selective Reporting of (Best Practice Guides Against) Selective Reporting

Mayo Memos for Meeting 5:

-Souvenirs Meeting 5: S: Preregistration and Error ProbabilitiesT: Even Big Data Calls for Theory and FalsificationZ: Understanding Tribal Warfare

Bonus meeting: 25 June: See General Schedule

-Selected blogposts on Significance Test Wars from March 2019:

  • March 25, 2019: “Diary for Statistical War Correspondents on the Latest Ban on Speech.”
  • June 17, 2019: “The 2019 ASA Guide to P-values and Statistical Significance: Don’t Say What You Don’t Mean” (Some Recommendations)(ii)
  • July 19, 2019: The NEJM Issues New Guidelines on Statistical Reporting: Is the ASA P-Value Project Backfiring? (i)
  • November 4, 2019: On some Self-defeating aspects of the ASA’s 2019 recommendations of statistical significance tests
  • November 14, 2019: The ASA’s P-value Project: Why it’s Doing More Harm than Good (cont from 11/4/19)
  • November 30, 2019: P-Value Statements and Their Unintended(?) Consequences: The June 2019 ASA President’s Corner (b) 
  • December 13, 2019: “Les stats, c’est moi”: We take that step here! (Adopt our fav word of Phil Stat!) iii

-ASA 2016 Guide’s Six Principles (PDF)

Slides & Video Links for Meeting 5:

Slides: Draft Slides for 18 June (not beautiful)

Video Meeting 5: (Viewing in full screen mode helps with buffering issues.)
       VIDEO LINK:

Meeting 4 (June 11)

getting beyond…

IV. (June 11) Rejection Fallacies: Do P-values exaggerate evidence? Jeffreys-Lindley paradox or Bayes/Fisher disagreement:


SIST: Excursion 4 Tour II

Recommended (if time): Excursion 4 Tour I: The Myth of “The Myth of Objectivity” 

Mayo Memos for Meeting 4

–Souvenirs  Meeting 4: Q: Have We Drifted From Testing Country? (Notes From an Intermission); R: The Severity Interpretation of Rejection (SIR)

FUN! Take a look at Richard Morey’s newly updated SEV app. It will display P-values, power and SEV (click display options). You can change the default by clicking the tab details and then using that link. Don’t forget to change the range of parameter values. If you change n to 25, you’ll get the answers to the example I gave in meeting #2.

  1. Solutions to problems given in Meeting #2: With X̅ =154 (PDF); with X̅ = 152 (PDF)
  2. Using the app for simple P-values: I wasn’t able to use the board to draw the curves for different P-values in meeting #2. Here’s how you can view them using Morey’s app for simple P-values. 

How do you interpret it? This just came out in NEJM (in defending policies based on antibody tests). “In the world of randomized clinical trials, statisticians test scientific hypotheses by requiring a probability of less than 5% that the observed result could have occurred by chance.” (Waiting for Certainty on Covid-19 Antibody Tests — At What Cost?)

-See details on Bonus Meeting: June 25.

Slides & Video Links for Meeting

Slides: (PDF)

Meeting 3 (June 4)

III. (June 4) Deeper Concepts: Confidence Intervals and Tests: Higgs’ Discovery:


SIST: Excursion 3 Tour III 

(Strongly) Recommended (as much as interests you) Excursion 3 Tour II:It’s the Methods Stupid: Howlers and Chestnuts of Tests

General Info Items:  

-References: Captain’s Bibliography

–Souvenirs  Meeting 3: N (Rule of Thumb for SEV), O(Interpreting Probable Flukes), [L (Beyond Incompatibilist Tunnels),M(Quicksand Takeaway]

-Summaries of 16 Tours (abstracts & keywords)

Excerpts & Mementos on Error Statistics Philosophy Blog

Mayo Memos for Meeting 3:

-5/30 I blogged on nearly every topic in SIST as I was writing it at Using the search on for a topic, you’ll often discover the development of ideas and discussion from readers. Reader discussion often saved me from blunders!

-A review essay of SIST by particle physicist Bob Cousins is relevant for the topics of meeting #3: Cousins, R. (2020). “Connections between statistical practice in elementary particle physics and the severity concept as discussed in Mayo’s Statistical Inference as Severe Testing” (Draft February 22, 2020), arXiv:2002.09713v1 [stat.OT].

Slides & Video Links for Meeting 3:

Slides: (PDF)


at-home seminar room w/ blackboard

(Thebes) conference room for seminar

amp & mike

on the desk outside conference room