| 1 In the file manager, the check file I've created has "recovered file fragments" as the file type. Is that correct? A: .chk is also the file type used by Windows when it checks your disk and finds orpha bits of files. You'll rarely, if ever, use or care about these files. I suggest you go to EpiData's options (File, Options), select the 'File Associations' tab, check all the boxes and click on 'Associate File Types'. Then all of your EpiData files will be properly described.

2 I've discovered I need to delete a number of variables from the data file. This seems straightforward since I can simply delete them from the .qes file and they will be deleted from the .rec file. What happens to the .chk file when I open the new .rec file with deleted variables? Will Epidata revise the .chk file by deleting the checks for variables that no longer exist?

You have two choices here. You may edit the chk file using File, Open. In the file dialogue, select the 'Files of type' to be 'EpiData check file (.chk)'. This brings up the full .chk file in EpiData's text editor. Just block the lines that begin with the name of the field you deleted and ending with its matching 'END' - this will be just before the next field name.

Or you can click on 'Check' in the workflow buttons. EpiData will ask you if you want to delete the lines for the fields you removed (respond 'No') or comment them out (respond 'Yes'). However, EpiData won't actually do these things unless you change something, or pretend to change something, so that the 'Save' button becomes active. So you can just click on 'Edit' for any field, click on 'Accept changes' and then click on 'Save'.

It is useful to get to know what .chk files look like inside, so I suggest the first option unless you are uneasy about editing files.

Jamie Hockin Public Health Agency of Canada