Sections on this page: General information sites, Files, Effect Size, Item Response theory
I’m always looking to add new resources to this page. If you have a favorite, please brooke{dot]robertshaw{at}gmail[dot}com.
Effect Size resources
- G*Power A very small, free, piece of software for running power analyses and effect sizes. For both Mac and PC. I love G*Power!
- UCLA: How is effect size used in power analysis: Includes a list of different effect sizes that can be computed and thresholds for different levels.
- Effect sizes information from the Cognitive & Brain Sciences Unit of the Medical Research Council, Great Britain: You can find thresholds for a variety of effect sizes as well as some explanations and references for more information.
- A whole bunch of effect size calculators, handy if you are doing a meta-analysis
- Another set of effect size calculators, less overwhelming
- A set of effect size calculators that includes non-parametric calculators and ways to convert between effect sizes.
- A free site at Utah State University, you can set up an account and run effect sizes and store them there. The developer of the site was a professor I worked with during my PhD
General Information sites
- StatNotes Books: A series of books you can buy that are, in my opinion, one of the best resources for SPSS. Each topic costs $5.00, but you can also download a pdf and request a password to access it for free. This is on a limited basis. They are also available for free through Kindle Unlimited.
- Note: Having used these, they are very, so very, worth the $5.00
- Annotated output at UCLA: Output of different tests from STATA, SPSS, SAS, R & MPlus with descriptions what each piece of information given means.
- Data Analysis Examples at UCLA:Introduction to the essence of different analysis techniques in SPSS, SAS, STATA, MPlus & R.
- Choosing the right statistical statistic at UCLA: A decision tree for helping to choose the right statistic.
- Frequently asked questions at UCLA: FAQs for general statistics questions, R, SAS, STATA, SPSS, MPlus, SUDAAN.
- Handbook of Biological Statistics: Yep, its useful even for those of us in the behavioral sciences.
- Quick Calcs: A site with some handy chi-square calculators, plus McNemars, and a couple of others. I’ve used it, very handy dandy.
- A website for computing Krippendorf’s Alpha
- Measuring Model Fit (SEM): Information on the different model fit indices.
- NYU Statistics: The R Project
- Research in Action Podcast: General discussion about resesearch and interviews with well known researchers, including John Creswell, Neil Salkind, and Jason Osbourne.
Survey research resources
- How to avoid the evils within customer satisfaction surveys: A great layperson’s explanation of survey mechanics, and addresses the need for reliablity and validity.
Files
- SPSS Basics Workshop slides: Covers opening data in SPSS, the data window, the variable window, transforming variables, running descriptives, chi-square, and correlation
- SPSS Intermediate Workshop slides: Covers charts and graphs, t-test, univariate analysis with 1+ factors, linear regression,
- Selecting Statistical Techniques by the University of Michigan, c 1985. (pdf, 7.5mb)
- Note: There is a more recent edition (1998) of this document, geared towards SAS users. Even though it is geared towards SAS users, it is still an EXCELLENT resource. It can be purchased from Powell’s books: Selecting Statistical Techniques For Social Science Data: A Guide for SAS Users.
- A reference for non-normal data where the parametric test is robust to violations of assumptions. (pdf, 135kb)
- SPSS Generalized Estimating Equation (GEE) Manual (pdf, 435kb)
- Stats 101b: A presentation to the Purdue Assessment Coordination Team covering ANOVA, effect size, small sample sizes, and cronbach’s alpha
Item Response Theory
- jMetrik: Free and open source software for running psychometric analysis (item response theory). There is a version for both Mac and PC.
- IRT Pro: An IRT software just for PC. I’ve used it and really like it. There is a free version that limits the number of cases (up to 1,000) and items that you can have.
- The Basics of Item Response Theory, by Frank Baker: From what I gather it is one of the key resources on the web for learning IRT.
- Item Response Theory resources: A page of resources created by the same folks who have made Baker’s book available.
- A visual guide to item response theory: As I am working to learn IRT this is another resource that is cited over and over.
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