bowald/chs-exam-statistics

chs-exam-statistics's Issues

NaN % fail rate

I stumbled upon a “NaN %” fail rate for TDA555 Introduktion till funktionell programmering. Same behavior in Safari on iOS 11 and Chrome 70 on Android. I haven’t looked at the code, but the detailed statistics seem to suggest that this specific instance arises from the exam of 2011-11-16. Maybe some kind of error handling or sanity check would be nice for such cases.

Great app btw!

Hosted version

Are you hosting a version of this somewhere? Pretty great stuff!

Average fail rate calculation

It seems to me that the average fail grade may not be correctly calculated. This depends on how "correctly" is defined, but these observations can be made:

Observation 1

The "average fail rate" today is literally the average of the fail rates, which gives greater weight to results performed at exams with fewer attendees. Consider as an (artificial, but illustrative) example a course which has given one regular exam and one re-exam, with the following statistics:

Regular exam

• U: 0
• 3: 99
• 4: 0
• 5: 0

Re-exam

• U: 1
• 3: 0
• 4: 0
• 5: 0

In total, the exam has been taken 100 times, with 1 failure. There are two ways to define "average fail rate":

1. The average of the fail rates, i.e. (0 % + 100 %) / 2 = 50 %. This definition is used in the app today.
2. The total number of failures over the total number of attempts, i.e. 1 / 100 = 1 %.

It is not obvious to me which of the definitions is better/more representative, but my spontaneous choice would be 2.

Observation 2

The "average grade" for passing performances is calculated analogously to definition 2 above, so one might expect the "average fail rate" to be calculated in the same way.

Broken link to Excel file

Your great Heroku hosted site is down! 😥

A possible issue might be that the link to the Excel file is broken!
http://document.chalmers.se/doc/00000000-0000-0000-0000-00001C968DC6

Bar graph of percentages

Nice feature that you can see the percentages. Would be even more awesome if you could see them the same way as the quantiles, i.e. a bar graph! (easier to compare different years).

Keep up the good work!

Data Source 404

Document Not Found
The document you requested does not exist. It might have been deleted.