OPL Problem Statistics

This article is under construction. Use the information herein with caution until this message is removed.

In a future version of WeBWorK (probably 2.12) the Library Browser will optionally display local and global data about problems, specifically the number of individuals who have attempted the problem, the average number of attempts on the problem and the average status earned on the problem. Local data represents usage at your institution and global data represents the sum of all local data contributions.

The display will look like

where obviously that data displayed in the image above is not real. This page provides information on OPL Problem Statistics for Instructors and WeBWorK Administrators.

Information for WeBWorK Administrators

The data that we are requesting you generate and contribute goes in a MySQL table OPL_local_statistics where entries look like:

+--------------------------------------------------+--------------------+------------------+----------------+ | source_file | students_attempted | average_attempts | average_status | +--------------------------------------------------+--------------------+------------------+----------------+ | Library/LoyolaChicago/Precalc/Chap4Sec2/Q02.pg | 2 | 3 | .5 | +--------------------------------------------------+--------------------+------------------+----------------+

so, as you can see, there is no student identifying data being requested.

In order to get this project (which is a small and independent part of the WeBWorK "Big Data" project) off the ground, we need global data. Hence this personal request for data from your institution.

If you are interested in contributing (and we hope you are), the process is very easy. First download two scripts with the following commands:

wget --no-check-cert https://raw.githubusercontent.com/goehle/webwork2/dbscript/bin/update-OPL-statistics wget --no-check-cert https://raw.githubusercontent.com/goehle/webwork2/dbscript/bin/upload-OPL-statistics

You can put them in /opt/webwork/webwork2/bin/ if you want. They should run on any recent version of WeBWorK but have only been tested on 2.7, 2.9 and 2.10. Run perl update-OPL-statistics which generates the OPL_local_statistics table. In the future you should probably run update-OPL-statistics at the end of every semester. It harvests data from all closed (due date has passed) homework sets and is written so that old data (e.g. from courses deleted since the last time the script was run or from courses that are reused by deleting old students and adding new ones or just old courses that remain on the server) is saved and new data is properly handled. It does not retrieve data from archived courses.

Then maybe you should contact your IRB office and tell them that you are planning on contributing data and show them the OPL_local_statistics table (or the sample above) so they can see that no student identifying data is involved. After receiving their blessing, to upload the data, run the command perl upload-OPL-statistics

That's it. Your local data will get sent to a server that Geoff Goehle (who has written most of the code for this project) is maintaining. The resulting OPL_global_statistics table will be distributed as part of the OPL.

If you are interested in seeing how this actually works in the Library Browser, do the following on your development system.

git checkout origin/develop git pull http://github.com/goehle/webwork2.git dbscript Update localOverrides.conf from localOverrides.conf.dist and run apachectl restart

Then run update-OPL-statistics if you haven't run that yet. Also it's a good idea to first update the OPL if you haven't done that in awhile. Either turn off the global data option (in localOverrides.conf) or create a fake OPL_global_statistics table, e.g a copy of OPL_local_statistics (maybe very soon with your help we will have a real OPL_global_statistics table available). Note that if no data is available for a problem you are looking at in the Library Browser, you will not see labels with 0's displayed.

Thanks for any help you can give us with this and feel free to write with any questions, comments or suggestions.

Sincerely,

Arnie