The Stat Server documentation (specifically the[i] User Guide[/i]) contains a complete list of stats available for configuration. Within Interactive Insights, the FACT Tables generally contain the stats you should be looking for - I am sure these are also defined in the associated documentation. A lot of users also define their own stats, as "composite" statistics in report templates, etc. so the actual list is quite literally endless...
A common misinterpretation for comparing WfM (Interactions) versus Standard Volumes is explained, here:
https://www.linkedin.com/pulse/apples-oranges-volumes-interactions-adam-gill?
An extract, in case the article is a long read;
[i]"For the purposes of WfM, an Interaction works differently. Through monitoring techniques and algorithms, WfM poses the same question, multiple times during call routing; Was there an appropriate resource available in the required time-frame? If the answer is "No", WfM will mark that Interaction as failed. If the call routing then expands to include other resources, WfM asks the question again; ...was there an appropriate resource available in the required time frame on the second leg? And it will continue to do this, for as many Target Groups that are presented. In this way, any by-product statistical ("Interaction") reports extracted from WfM will be, by definition, larger than those of ("Volume") reporting, offered in the standard Reporting tools.
The bottom line is that [i]Volumes [/i]and [i]Interactions [/i]are not measuring the same metric - nor the same work effort. If you assume that they do - or that they should - it can lead to bad practices in BI reporting, where manual updates or "fixes" might be employed, to ensure both values match."[/i]