Launch the Item Analysis platform by selecting Analyze > Consumer Research > Item Analysis.
Item Analysis Launch Window
Tip: Use Cols > Recode if you need to recode your data to 0s and 1s. See Recode Valuesin the Discovering JMP book.
If you select Logistic 3PL for Model, you are prompted to enter a penalty for the guessing parameters after you click OK. For a 3PL model, the default value of the penalty is zero. However, you can enter a non-zero penalty for the c parameters (the guessing for each item). This penalty is similar to the type of penalty parameter that you would use in ridge regression. The penalty is on the variance of the estimated guessing parameters. The use of the penalty has the following benefits:

Help created on 9/19/2017