In distributed applications, we need to put special emphasis on issues such as network latency, low bandwidth. Hence as a good design principle, we should make our interfaces 'chunky' and not 'chatty'
Chatty interfaces are interfaces that make a lot of transitions(between layers, processes etc.) without doing any significant work on the other side. For example, property setters and getters are chatty. Chunky interfaces are interfaces that make only a few transitions and work done on the other side is significant. For example, method that opens a database connection and retrieves some data is chunky.
This does not mean that U return unnecessary data in Ur calls...U need to take a decision based on 'balance' and the 'problem situation'