Instructions or doc for recording and using "web transaction" service tests?

I have recorded a few "web transaction" service tests for Web apps defined as generic services, but I think all the playback is really doing is bringing up the first web page. The service tests do fail if the web service is down, but when the web service is up they all execute very quickly, despite the fact that one test should retrieve a page of data that should take several seconds to retrieve. Hence I do not think the "test" is doing everything that I recorded. The documentation seems very superficial, telling you how to define a service and