DCS grading programs

Sending grades files by mail

Course instructors and TAs nearly always want to exchange grades files by e-mail. 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:

1. 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.)

2. E-mail programs kill tabs. 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. I've had trouble sending with my Unix mailer to a TA with a PC mailer, and I've had trouble sending with my PC mailer to a TA with a Unix mailer. The result is guaranteed trouble.

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 genter 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.

• Get me to write a better grading-file editor than genter.

Try to keep mailers from losing tabs.

• Send marks files as attachments instead of as text.

  This will be a nuisance in a Unix environment. However, if you receive attachments with a Unix mailer then you can use the metamail command to decode them, at least on CS Lab machines. Elsewhere, there may be similar attachment-decoding commands, or there may be a PC-like environment available.

• Replace tabs with something else.

  It looks funny, but you can use another character instead of the tab to delimit marks. Obviously, it needs to be a character you're not likely to want to use elsewhere; at least one instructor has 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 genter, 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.