CloseCATs

CloseCATs is a card game where:

• Two cards are dealt to the computer and two to the player
• The card in row 1 represents the random slope variance
• The card in row 2 represents the random effect covariance
• The player has an option to switch their row 1 and row 2 card (the computer does not)
• Data is simulated from a mixed effects model defined by the game setup and the cards
• Simulated data is fitted to the data generating mixed effects model, a random intercept model, and CATs models
• A misspecification distance (rmse of CATs - rmse of random intercept) is computed for the computer and for the player
• The lower misspecification distance wins the game

The game was designed to help users get a better understanding of when to prefer a CATs model over a random intercept model.