In this blog post, Mike Long discusses the current trend to design applications for specific users or “personas”. His point is that “focusing on individuals might improve things for one person at the cost of others.” He prefers instead Activity-Centered Design (ACD) that focuses on the activity context in which individuals interact with the product.
Persona have become the center of human-centered design (UCD), but they are a proxy for real customer when they are not participating enough to the project. According to Mike, using personas increases the risk of feature bloat. Instead of analyzing individuals as personas, you should analyze the situation from an activity perspective using a human activity diagram. The post explains how to draw this diagram with a concrete example.