That's right. There are a variety of different schemes that have been devised by the pool operators to enact fair compensation for the pool workers. Most pools pay proportional to the amount of work that the worker accomplishes with a fee for the operator. But there are many of tweaks and variations, some of which are to deal with bad actors (pool skipping) or to allow for a steady pay out to the workers in the face of the unpredictable variability in time between coins that the pool successfully mines.

https://en.bitcoin.it/wiki/Comparison_of_mining_pools