November 19: “Randomisation and control in the age of coronavirus?” (Stephen Senn)

The third meeting of our New Phil Stat Forum*:

The Statistics Wars
and Their Casualties

November 19: 15:00 – 16:45  (London time)
10-11:45 am (New York, EST) 

“Randomisation and Control in the Age of Coronavirus

Stephen Senn

ABSTRACT: Many critics of randomisation have assumed that it is supposed to guarantee balance of prognostic factors, proceeded to show that this is impossible and then concluded that the theory is flawed. However, the shocking truth about randomisation is exactly the opposite of what they suppose. If we knew that all prognostic factors in a randomised clinical trial were balanced, the standard analysis of such trials would be wrong. The analysis that Fisher proposed for randomised experiments makes an allowance for factors being unbalanced. I shall show how this fundamental misunderstanding of how the randomisation and analysis combination deals with error is the origin of a serious error in interpreting trials. I shall illustrate the points with a game of chance and an actual trial. I conclude by recommending that would-be commentators should not presume to analyse the logic of trials until they have analysed some results.

Stephen Senn is a consultant statistician in Edinburgh. His expertise is in statistical methods for drug development and statistical inference. He consults extensively for the pharmaceutical industry in the UK, Europe and the USA on: planning of clinical trials and drug development programmes, project evaluation and prioritization, regulatory advice and representation, data safety monitoring board advice, specialist analyses, and statistical training. Stephen Senn has worked as a statistician but also as an academic in various positions in Switzerland, Scotland, England and Luxembourg. From 2011-2018 he was head of the Competence Center for Methodology and Statistics at the Luxembourg Institute of Health in Luxembourg. He was a Professor in Statistics at the University of Glasgow (2003) and University College London (1995-2003). He received the George C Challis Award of the University of Florida for contributions to biostatistics, 2001 and the PSI Award for most interesting speaker in 25 years of PSI in 2002. In 2009, he was awarded the Bradford Hill Medal of the Royal Statistical Society. In 2017 he gave the Fisher Memorial Lecture. He is an honorary life member of PSI and ISCB.

Information about the Phil Stat Wars forum and how to join is here. 


Readings:

For related posts on randomization by Stephen Senn, see these guest posts from the Error Statistics Philosophy blog:

Slides and Video Links:

Stephen Senn’s slides: Randomisation and Control in the Age of Coronavirus

Stephen Senn’s presentation:

Discussion on Senn’s presentation:

 


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

*Meeting 11 of our the general Phil Stat series which began with the LSE Seminar PH500 on May 21

The P-Values Debate

 

National Institute of Statistical Sciences (NISS): The Statistics Debate (Video)

 

The Statistics Debate

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

Website: https://www.niss.org/events/statistics-debate
(Online webinar debate, free but must register to attend on website above)

 

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

Participants:
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

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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.

Readings:

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: https://richarddmorey.github.io/TalkPhilStat2020/#1

Video Link to Morey Presentation: https://philstatwars.files.wordpress.com/2020/09/richard_presentation.mp4

Video Link to Discussion of Morey Presentation: https://philstatwars.files.wordpress.com/2020/09/richard_discussion.mp4


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)

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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.


SLIDES & VIDEO LINKS FOR MEETING 8:

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

Delayed (from 19-20 June 2020*) is now a monthly remote forum** 

*London School of Economics (CPNSS)

Alexander Bird (King’s College London), Mark Burgman (Imperial College London),
Daniele Fanelli (London School of Economics and Political Science),
Roman Frigg (London School of Economics and Political Science),
David Hand (Imperial College London), 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)*

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]

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: https://www.niss.org/events/statistics-debate. (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)

December 17, 2020 (15:00-16:45 (London); 10-11:45 a.m. (New York) EDT): D. Mayo (Philosophy, Virginia Tech (mini-bio)) TBA but might do a long promised talk on Birnbaum and the Likelihood Principle.

January 28, 2021 (15:00-16:45 (London); 10-11:45 a.m. (New York) EDT): Alexander Bird (Philosophy, King’s College London,Bertrand Russell Professor, University of Cambridge (mini-bio)). TBA

February 18, 2021 (15:00-16:45 (London); 10-11:45 a.m. (New York) EDT)Christian Hennig (Statistics, University of Bologna (mini-bio)). TBA

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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:

DRAFT OF Mayo JSM 2020 SLIDES (PDF)

FINAL Mayo JSM 2020 SLIDES (PDF)

 

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”

Reading:

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:
https://wp.me/abBgTB-mZ

VIDEO LINK to David Hand’s Presentation: https://wp.me/abBgTB-mS
David Hand’s recorded Powerpoint slides: https://wp.me/abBgTB-n4
AUDIO LINK to David Hand’s Presentation & Discussion: https://wp.me/abBgTB-nm

Another link is here.

 

Meeting 5 (June 18)

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

Reading:

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: https://wp.me/abBgTB-n8

Meeting 4 (June 11)

getting beyond…

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

Reading:

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?)  https://www.nejm.org/doi/full/10.1056/NEJMp2017739?source=nejmtwitter&medium=organic-social

-See details on Bonus Meeting: June 25.


Slides & Video Links for Meeting

Slides: (PDF)