B. Data Preparation questions

Q1. I have trouble making my own dataset work. What should I do?

A1. We suggest you first try to download the dataset from our web site. If you can follow the tutorial and have no trouble using the dataset, it is likely that there is something wrong with your dataset. For example, the file format or the dataset format is not recognized by the program.

Q2. I still have trouble making my own dataset work. What should I do?

A2. At B. Data Preparation for IRT Analyses, we suggested using SPSS to format the data; although other statistical programs may also be used. The data must eventually be saved in ASCII format as a *.DAT file in order for the IRT programs to access it. For instance, we used the first four characters as the Subject ID. Thus, every entry must begins with a 4-digit ID (e.g., 1001 or 0001), as opposed to having fewer digits (e.g., 1).