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PSY 626: Bayesian Statistics for Psychological Science


Spring 2024
Days/times: Tuesday, Thursday / 12:00 pm - 1:15 pm
Location: PRCE 255

Instructor:

NameOffice EmailPhoneOffice hours
Greg FrancisPSYCH 3186gfrancis@purdue.edu494-6934 MWF 11:00 am - 12:00 pm

Materials (lectures, readings, datasets, code):

This material can be downloaded from the class website at http://www2.psych.purdue.edu/~gfrancis/Classes/PSY626/indexS24.html

Text:
Rethinking Statistics web site McElreath, R Statistical Rethinking: A Bayesian Course with Examples in R and Stan. Try to get the second edition. Ordering information and code examples are at the book web site.

In case you do not yet have the textbook, Chapters 1 and 2 of the textbook are on-line.

As mentioned in class, you might want to install the rethinking package on your own computer. Here some guidance for a modern Mac (note the dependencies near the top).

General guidance is at the rethinking GitHub. Note, you cannot get by with just the slim install because we will soon need the MCMC algorithms.

The TA made an R script that might help, but I think you still need to first install a C-compiler.

General plan: The course will explain why you might want to use Bayesian methods instead of frequentist methods (such as t-tests, ANOVA, or regression). The general plan is to:

  1. Explain some problems/difficulties with frequentist methods: Publication bias, optional stopping, questionable research practices.
  2. Discuss differences between hypothesis testing and prediction: mean squared error, shrinkage.
  3. Discuss methods for prediction: likelihood, AIC, BIC, cross-validation.
  4. Explain the basic ideas of Bayesian methods: non-informative priors, informative priors.
  5. Provide hands-on examples of applying Bayesian methods: Bayes Factors, hierarchical models.

Throughout, we will be using computer programs to demonstrate the ideas. There will not be any proofs.

Class home page: The home page for this course is http://www.psych.purdue.edu/~gfrancis/Classes/PSY626/indexS24.html From this page you can download lecture notes, view the class schedule, view current grades, and connect to the various homework laboratory assignments.

Homework: Assignments will be due approximately every two weeks. The intention is to use the homework assignments as a way of practicing the concepts we discuss in class. They will be graded, but only to insure that students actively participate.

  1. Homework 1 (due date corrected): as PDF, as MS Word, ComputePower.R,
  2. Homework 2 (due February 5): as PDF, as MS Word, SleepySubjects.csv,
  3. Homework 3 (due February 26): as PDF, as MS Word, HummingRT.csv
  4. Homework 4 (due March 18): as PDF, as MS Word, Learning.csv (updated to fix a columns issue)
  5. Homework 5 (due April 18): as PDF, as MS Word, EmotionalStroop.csv

Project: In the last two weeks, students will present a Bayesian (or related) analysis of some of their own data. If you do not happen to have a data set, we will get one for you. There is no formal requirement for what to include in the project, but here's a few thoughts.

Assumed background:

Teaching Assistant:

Name OfficeEmailOffice hoursZoom
Dani LarranagaPSYCH 3172dlarran@purdue.edu Tuesday, Thursday 1:30 - 3:00 pm https://purdue-edu.zoom.us/my/danimcgo
Please contact the TA if you cannot meet during office hours to schedule an alternative time.