Sentence:  Interestingly enough - although none of the real-life therapists involved could conceivably compare with Blauberman - when groups of them <WSD>began</WSD> playing back interviews , they discovered any number of ways in which they wanted to polish their own interview techniques ; almost everyone , on first hearing one of his own sessions on tape , expressed some desire to take the whole thing over again . 
Meaning of the word marked with <WSD> tags:  take the first step or steps in carrying out an action