The following are types of data sent back by an activity

More info on this can be seen here: http://www.telscenter.org/confluence/display/SAIL/Model+Logging+and+Reporting

"Dribble" Log

There is a "dribble" log which should records as many student actions as the network connection can resonably handle.
This could be at the level of mouse movement or clicks.
Or it could be at the level of UI events like:

• button2 was clicked.
• text2 was modified with "blah blah"

Semantic Logs

There are one or more semantic logs which use logged and unlogged actions and turn them into something more meaningful.
Examples of this are taking the button clicks that start and stop an interactive model. And saving something like:
http://www.telscenter.org/confluence/display/SAIL/Model+Schemas.

Reports

In this case the activity process the dribble log, and or a sematic log. And creates a human readable report which sumarizes the log data. For example:
The student ran the model 5 times.
The student tried using all of the controls in the model.