The Config.txt file is the information file that the FreeIAT uses to setup and run your IAT.
When you start the FreeIAT program, the first thing the program does is to look for a “Config.txt” file in the same directory as the FreeIAT.exe program. This directory is considered the root directory by the FreeIAT program, no matter what the path extension is of the directory. The Config.txt file must appear in the same directory as the FreeIAT.exe program. Be aware that if you have a desktop shortcut, the configuration and other files must be in the same directory as the FreeIAT.exe file, not on the desktop. Your data will be written to this directory as well.
Text Only v. Image and Text IATs
One set of stimuli in the IAT must be text. The other set, however, can be text or images. The choice of text versus images impacts the Config.txt file in that different commands are used to specify text as the second set of stimuli versus images as the second set of stimuli.
Some basic rules of FreeIAT commands:
- All commands are designated by surrounding the command in a pair of brackets.
- The bracketed command should appear in the first column of the line .
- Each command must appear on a new line.
The following commands are required in all IATs:
|Title||Specifies title of IAT (displayed on intro screen and appears in output)||Limit to 150 characters||[Title] Race IAT|
|Stimuli-1 Label||Label of first category of IAT text stimuli||Limit to 40 characters||[Stimuli-1 Label] Positive Words|
|Stimuli-2 Label||Label of second category of IAT text stimuli||Limit to 40 characters||[Stimuli-2 Label] Negative Words|
|Stimuli-1||Word stimuli to be included as part of the first category of text stimuli||Limit to 50 characters||[Stimuli-1] Joy|
|Stimuli-2||Word stimuli to be included as part of the second category of text stimuli||Limit to 50 characters||[Stimuli-2] Agony|
|Stage-X Trials||Number of trials for Stage X. Replace “X” with the stage/block number.||Must be a positive integer. Must have 5 such commands, one per stage.||[Stage-2 Trials] 50|
Commands for Text-Only IATs:
|WordSet-1 Label||Label of first category of second set of IAT text stimuli||Limit to 40 characters||[WordSet-1 Label] Insect|
|WordSet-2 Label||Label of second category of second set of IAT text stimuli||Limit to 40 characters||[WordSet-2 Label] Mammal|
|WordSet-1||Word stimuli to be included as part of the first category of the second set of text stimuli||Limit to 50 characters||[WordSet-1] Ant|
|WordSet-2||Word stimuli to be included as part of the second category of the second set of text stimuli||Limit to 50 characters||[WordSet-2] Monkey|
Commands for Text & Image IATs:
|ImageSet-1 Label||Label of first category of IAT image stimuli||Limit to 40 characters||[ImageSet-1 Label] African Americans|
|ImageSet-2 Label||Label of second category of IAT image stimuli||Limit to 40 characters||[ImageSet-2 Label] European Americans|
|ImageSet-1||Image stimuli to be included as part of the first category of image stimuli||Limit image sizes (maximum size will depend on the computer monitor resolution). Not all image file types have been tested, however .jpg and .gif are known to work.||[ImageSet-1] Black_1.jpg|
|ImageSet-2||Image stimuli to be included as part of the second category of image stimuli||Limit image sizes (maximum size will depend on the computer monitor resolution).Not all image file types have been tested, however .jpg and .gif are known to work.||[ImageSet-2] White_1.jpg|
* Requirements are not formal system requirements. However, display issues may be encountered when labels, titles, etc are excessively long.
How the Config.txt file reads data
Once the FreeIAT program finds the Config.txt file, it begins reading the file line by line. If the line contains a recognized command, the line is read, otherwise it is ignored. As a result, you can comment the configuration file as much as you would like. The program will simply ignore these comments. No special characters are need to specify comments.
If the line in the program is a recognized command, the line will be read. There is no special order in which commands must appear in the configuration file. If the command is a title, category label, output delimiter, or indication of the number of trials per stage, those values will be stored in a single “block” of memory in the order which they are encountered. As a result, should you happen to have two title commands (for example), only the one that appears last in the file will be stored.
Conversely, stimuli themselves are stored into an multi-dimensional array immediately once they are encountered. As a result, if a particular word (e.g., “happy”) appears twice in the command file, it will be treated as two independent stimuli. There is no limit as to the number of stimuli that you can present. There is also no need to tell the program how many stimuli you have. After all commands are read from the file, the program will automatically calculate how many stimuli appear in each category. There is no requirement to have an equal number of stimuli per category (e.g., it is OK to have 10 positive words and only 8 negative words).
Placing Image Stimuli in Sub-Directories
Text stimuli must be specified in the Config.txt directly, not in an external file. Pictures and images, on the other hand, should be referenced by their file name. Spaces are allowed in these file names. By default, the FreeIAT will check for image stimuli in the same directory as the FreeIAT.exe program (i.e., the root directory). It is not possible to specify a different directory for these images, however, a sub-directory within the root directory may be specified.
As an example, suppose the FreeIAT.exe file is located in the directory “C:/FreeIAT/”. This directory is the root directory and if an image (e.g., “Male1.gif”) is specified as a stimulus command, the FreeIAT will automatically search for “C:/FreeIAT/Male1.gif”. However, suppose the file Male1.gif was stored in a subdirectory called “Images”. To specify this, the command should be given such that the image is called “Images/Male1.gif”. The FreeIAT will then search for “C:/FreeIAT/Images/Male1.gif”. Multiple sub-directories may be specified in this same way, however the path of the root directory may not be altered. As an example, if the command stated that the image to search for was “C:/IATstimuli/Male1.gif” yet the FreeIAT.exe was located in the “C:/FreeIAT/” folder, the program would search for “C:/FreeIAT/C:/IATstimuli/Male1.gif” and would return an error.
Images must not be excessively large. The IAT doesn’t not resize images, rather it centers them as they appear. Many web sites allow images to be easily resized or cropped for free (just try searching for ‘resize images’ in a search engine). Note that different computer monitors will have different resolution so large images should be pilot tested and resized as needed.