F1. DIF/DTF questions

PARTO3PL, PAR_3PL, PAR3PLMG, ParConversion questions

Q1. What do programs like PARTO3PL and PAR_3PL do?

A1: PARTO3PL and PAR_3PL will convert only original BILOG generated parameter files (*.PAR) by 1) delete the first four lines and 2) subsequent alternating lines, 3) create output file using the *.3PL extension by following the 32x,2f12.6,12x,f12.6 format (which can be used for running ITERLINK), and 4) create output file using the a,b,c (free-field) format (e.g., *.TXT).

Q2. What do programs like PAR3PLMG do?

A2: Similar to PARTO3PL and PAR_3PL, PAR3PLMG convert only original BILOG-MG generated parameter files (*.PAR) by 1) delete the first four lines, 2) remove standard error columns, and 3) create output file using the *.3PL extension by following the 32x,2f12.6,12x,f12.6 format (which can be used for running ITERLINK), and 4) create output file using the a,b,c (free-field) format (e.g., *.TXT).

Q3. What do programs like ParConversion do?

A3: ParConversion will convert only original BILOG generated parameter files (*.PAR) by 1) delete the first four lines and 2) subsequent alternating lines, and 3) create output file using the a, b, c (free-field) format (e.g., *.TXT). That is, the program will only retain 3 columns of parameters a, b, c only in a 3PL model (from columns 4, 5, and 7 of original BILOG's '*.PAR' file) after removing the first 4 rows of title/comment information and alternative rows thereafter that contains standard errors.

Q4. I have trouble running PARTO3PL and PAR_3PL. What should I do?

A4: If both programs crash, you may want to use Excel to open your *.PAR file, record a macro such that it will delete the first four lines (title/comment information) and subsequent alternating rows (standard errors). Alternatively, you may try running ParConversion. Please notice that the file formats (i.e., *.3PL) generated by PARTO3PL and PAR_3PL are different from files generated by ParConversion program (i.e., *.TXT).

Q5. I have trouble running ParConversion. What should I do?

A5: ParConversion requires Microsoft .NET Framework update. You may obtain the update through Windows Update. If for some reason ParConversion does seem to be working (Conversion will be completed automatically once the '*.PAR' file selection is done and will be saved in the '*.TXT' format with parameters only. The program runs very fast!).