When you run your system library or historical test, relative strength generation, or bad data checking, you have the choice of using all of your data files or just specific data files.
Most investors will want to use (and are encouraged to use) all of their data files for testing purposes. This will give you much more accurate testing results, since you will have a larger sample size. (See the Statistics section). However, some investors may want to test just a small subset of files to optimize testing parameters before they test all of their data files to see if the optimizations hold true on a larger set. Similarly, some investors may recognize that certain files will typically contain more bad quotes than other files, so they may want to check for bad data on just specific files.
Groups give you the ability to test, etc., on just the few files that you want. You can create and change groups by using the Groups dialog box. You can change data type and directory information by using the Change Data Type Parameters dialog box.
Please note that both of the above dialog boxes allows to choose whether you want to test on all of your data files or whether you want to test just on your groups. Also note that just because you have checked either option, it does not necessarily mean that all of the data files or groups will be tested. If you have changed the use of a group or data directory to No, even though the desired data file or group option is checked, the specific group or data file will not be tested. The flow chart below shows how Investigator chooses which files to use.
First, are you using Data Files or Groups?
If you are using Data Files, Investigator looks at each directory associated with each data type to see if you want to use that directory, signified by a “- Yes” or “- No” after the Current Data Directory name in the Change Data Type Parameters dialog box. If the directory has a “- Yes”, the directory will be used. If the directory has a “- No”, the directory will not be used.
If you are using Groups, Investigator looks at each of your current groups to see if you want to use that group, signified by a “- Yes” or “- No” after the Current Group name in the Groups dialog box. If the group has a “- Yes”, the Current Files in that group will be used. If the group has a “- No”, the Current Files in that group will not be used.