A series of video tutorials by W. Joel Schneider
1. Variables and Measurement Scales
2. Frequency Distributions
3. Probability Density Functions
4. Expected Value: What Does the Mean Mean?
5. Expected Value and Variance: Take a Moment or Two to Find Out How the Mean and Variance Are Alike
6. The Normal Distribution and the Central Limit Theorem: Sum of the Many Reasons Variables Are Normally Normal
7. Skewness: Lopsided Variability
8. Kurtosis: Beyond Peakedness
9. Standard Scores and Why We Need Them
10. Covariance
Additional Videos
Two Kinds of Hierarchies in Cognitive Ability Models
A Taxonomy of Influences on Ability Tests
Within-Composite Differences: Why Measures of the Same Ability Differ
Do Large Subtest Differences Invalidate Composite Scores?
A Geometric Representation of Composite Scores
What if We Took Our Models Seriously? Estimating Latent Scores in Individuals
Misunderstanding Regression to the Mean
Contact Me: Joel Schneider wjschne@ilstu.edu
Assessing Psyche, Engaging Gauss, Seeking Sophia 
Excellent explanations, even for a marginally statistically literate person, like me.
Best wishes, Ruben, Moreno Valley Unified School District,CA
Thanks Ruben!
One of the reasons that I am doing this is to become less marginally literate myself.
Joel, I agree with Ruben. If I weren’t so grateful I’d be downright embarrassed (and who knew there were two ‘r’s in embarrassed? thank goodness for spellcheck!). Seriously, you are providing a terrific service and I am very grateful.
Best,
Tom
Thanks Tom!
A stress-saver. I was scratching my head and saying “oh, no …” to myself over 2 clients with very low academic skills despite mid-average intelligence and a cognitive processing factor about 20th %ile. Your video showed me that such factors don’t have the ‘power’ I assumed they had, as even one at 5th %ile can’t be assumed to have explanatory value. Thanks for this information.
Shocking, isn’t it? It went against all my intuitions. Glad to be of help.