Course instructors and TAs very often want to exchange grades files by email. It works, but not so easily as you'd think.
What's the problem?
The trouble is tabs. The grades files use tabs to delimit mark entries. Specifically, before each mark in a student record is a tab. If a mark is missing, its tab must still be present, unless all later marks for that student are also missing.
Tabs cause trouble for two reasons:
- People entering grades (that's you, if you're a TA) use
blanks instead of tabs to make the marks line up. Or they
insert extra tabs to make marks line up when they shouldn't.
(When should marks not line up? — when student names are of varying length. To add enough blanks after each name to make nearly all names line up, try gpadnames.)
- Email programs kill tabs, unless you are careful to send grades files as attachments rather than in-line. Many mailers work fine with themselves, but have trouble if they interact with other mailers, and there are a lot of mailers out there. If you're an instructor with five TAs, then you have a couple who use Unix mail programs and three who use PC mail programs. Mixing platforms as well as mailers is a recipe for trouble.
(In case you're thinking, why use tabs at all?, you might like to know that in the 1988 version, columns of marks had to be lined up with spaces. TAs would use tabs to make things look right with less typing. You can't win.)
What can you do?
I don't have a complete solution, but here are some ways to alleviate the problem.
Don't mess up the tabs yourself.
- Use grades to enter marks; it keeps track of where tabs should be for you.
- If you must use a text editor, use one that doesn't mess up tabs, and follow the tab rules yourself: one tab before every mark (even missing marks), and no tabs anywhere else. Also, make sure you're using "hard tabs" (with actual tab characters) rather than "soft tabs" (using blanks to simulate the spacing that tabs would produce).
Try to keep mailers from losing tabs.
- Send marks files as attachments instead of as text.
- Replace tabs with something else.
The grading programs allow you to separate marks with another character instead of tabs. The files can be hard to read, but few other characters are subject to the same difficulties as tabs. Obviously, you need to pick a character you're not likely to want to use elsewhere; at least one instructor had good results with the tilde, '~'.
To get your marks file to use tildes instead of tabs, you must make the first line in your file start with these three characters: "
*/~".Similarly, to use the vertical-bar character in place of the tab, your file must begin with "
*/|".
Reduce the damage caused when tabs are lost.
- Just send one column of marks by mail.
If you're a course instructor, you can make up a "transmission-only" marks file for a TA by omitting all mark definitions from it except the one you're interested in, and removing all mark values completely.
This file will have no tabs in it at all. You mail it to the TA, who puts marks at the end of the lines — perhaps correctly, with grades, or perhaps not — and mails it back to you. The mail programs between the TA and you may treat the tabs correctly, or they may not, but it will be quite clear which students have marks and which don't.
You repair the file, check it with glint, and copy the marks to your main marks file with gcopy.