Respondus 4 does not download raw data to generate reports but instead uses “browser emulation” to capture the reports generated by Blackboard. It’s the same process as an instructor going into the Blackboard course Grade Center to create the various reports.
Go to the "Retrieval and Reports" tab and you'll see the various reports that are available for retrieval from the Blackboard Learn course.
For statistical analysis, one idea you might consider is to use Respondus-Retrieval & Reports-Download Data to download the data file generated by Blackboard and then use another stats package (SysStat, MiniTab, Excel, SAS, SPSS, etc) to do additional analysis.