Data quality and completeness
The collection of activity data is not at this time a normal procedure, and thus institutions have, naturally enough, not concentrated on maintaining and assuring the quality of applicable data sources. While this currently presents some problems, we view this as a transient situation that will improve over time.
A general picture is portrayed by the EVAD Project at Cambridge:
"First, we've had to get our data (first, catch your rabbit..), from when we started using CamTools (our current institutional VLE) to December 31 2010. This involved retrieving archived data, which didn't go as smoothly as we ’d hoped. We had to do some restoration of corrupted data, and we ’re missing about two weeks of data as well. This just illustrates the problems of dealing with data that’s collected but not looked at very often."
Other projects also ran into problems as discussed here