Final answer:
Leveling is the technique used by an analyst to start with an overall view in a context diagram and then create a more detailed diagram 0.
Step-by-step explanation:
Using leveling, an analyst starts with an overall view, which is a context diagram with a single process symbol, and then the analyst creates diagram 0, which shows more detail. Leveling is a technique used in process modeling and systems analysis to depict a complex system in a manageable and understandable way.
The context diagram, or level 1, is the most abstract level, showing the system as a whole with its inputs and outputs. Diagram 0, which is a more detailed view, contains multiple processes that interact with each other and with external entities, breaking down the high-level process shown in the context diagram into its components.