Instructions for dMACS.exe

The following instructions can be used to calculate the dMACS effect size measure developed by Nye and Drasgow (2011) using the dMACS computer program developed by Nye (2011).

First, be sure to change the file from dMACS.xex to dMACS.exe. Then, there are two options for running the program. The first option is to double-click on the dMACS.exe program and manually enter the appropriate information for each of the questions. When using this option, all files should be in the same folder as the program and full file names should be entered. Remember to include the extension (e.g., .txt, .doc, .dat) in each file name.

Because a large amount of information is required for calculating the effect size, a more efficient approach is to use the batch file included in the folder with the dMACS program. Take the following steps to run the program using this approach:

Step 1. Open dMACS_input.run in a text editing program.

Step 2. Change the entries in the .run file to correspond to your files. Below are the annotated entries from the .run file:

4 (the number of items in the test)

0 (the minimum value[1] of the latent trait that you would like to evaluate)

6 (the maximum value[2] of the latent trait that you would like to evaluate)

Example_loadings_group1.txt (the file with the factor loadings for the reference group)

Example_loadings_group2.txt (the file with the factor loadings for the focal group)

Example_intercept_group1.txt (the file with the intercepts for the reference group)

Example_intercept_group2.txt (the file with the intercepts for the focal group)

Example_PooledSD.txt (the file with the pooled standard deviation for each item)

Example_Latent_Mean_group1.txt (the file with the mean of the latent trait in the reference group)

Example_Latent_Mean_group2.txt (the file with the mean of the latent trait in the focal group)

Example_Latent_Variance_group1.txt (the file with the variance of the latent train in the reference group)

Example_Latent_Variance_group2.txt (the file with the variance of the latent train in the focal group)

Example_Error_Variance_group1.txt (the file with the variances of the measurement errors in the reference group)

Example_Error_Variance_group2.txt (the file with the variances of the measurement errors in the reference group)

Example_output.txt (name of the output file)

Step 3. After changing the entries in dMACS_input.run, save and close the file.

Step 4. Double-click on the batch file labeled Run_dMACS.bat. This will automatically run the computer program and create an output file with the name specified in the .run file.

[1] The minimum value of the latent trait should be one less than the score for the lowest possible response option. For example, if you are using a measure with a five-point Likert response scale that ranges from 1 to 5, you should enter a 0 for this entry in the .run file.

[2] The maximum value of the latent trait should be one more than the score for the highest possible response option. For example, if you are using a measure with a five-point Likert scale that ranges from 1 to 5, you should enter a 6 for this entry in the .run file.