This is Bales' schedule of categories of group interaction types. The problem in devising such a grid, which might be used as the basis for observation, is, of course, to provide categories which are sufficiently numerous as to cover what are perceived by the observer to be significant differences, whilst at the same time keeping the number of categories small enough to allow the observer a ready overview of them.
Bales' IPA is often used as the basis for developing group observation record sheets. Typically, such a sheet will be used, along with sociograms, by observers to record the dynamics of a group interaction. If you would like to take a look at such a sheet, please click here: