As a data modeling expert in your company, you are frequently being asked modeling advice. After dazzling your coworkers with a clear explanation as when to use surrogate keys (see Design Challenge #16, To surrogate key or not to surrogate key), you have received a big promotion and a corner office near the CIO's office. The CIO is now asking you for frequent advice, including this request: "I have heard a lot of buzzwords at a recent business intelligence gathering. Give me a short yet complete explanation for aggregation, summarization, and abstraction."