Elaborative vs. maintenance rehearsal
Elaborative rehearsal involves meaning-based analysis - thinking about the meaning of an item, and thus making a connection between the item and previously learned knowledge. Maintenance rehearsal, on the other hand, does not involve semantics - it is the simple repetition of an item without taking into account its meaning or relation to other items.
Some mechanisms of encoding are more effective than others in transferring information into long term memory. Maintenance rehearsal helps maintain information in short term memory but is not an effective way of transferring information into long term memory. Elaborative rehearsal is a good way to establish long term memories.
The distinction between elaborative and maintenance rehearsal is significant because cognitive psychologists were correct in their hypothesis that taking semantics into consideration when rehearsing would produce superior memory.