Topic 
Link to app 
Description 
Trigonometry 
Unit Circle 
Geometric interpretation of the sine and cosine functions using
a cirlce with radius of one. 
Spelling 
Spell test 
Can you choose between correctly and incorrectly spelled versions of
21 difficult words? 
Statistics 
SLR model 
Simulate from the simple linear regression model. The focus is on
the differences between the parameters and their estimates and between
the errors and the residuals 
Power curve 
Power curve for the twosample t test and its dependence on the
effect size, standard deviation, sample size, and significance level 
Norm Quant Plot 
Produces normal quantile plots for simulated data from different distributions
(normal and nonnormal) and explains what is plotted on the x and yaxes.

Leverage 
Displays how leverage is a measure of the statistical distance of the x
values for an individual from the center of the xvalues for the dataset.

Model Selection 
Shows the bias/variance tradeoff involved in model selection. Specifically,
underfitting can lead to bias in the regression coefficient estimates and overfitting
can lead to increased variance.

Onefactor fixed/random 
Oneway fixed/random effect models 
Three Factor 
Shows the effects of each term in the 3factor effects model on the cell means 
Two factor 
Simulating from twofactor models with crossed/nested and
fixed/mixed/random factors 