Sunday, February 01, 2004
By evaluating an API with respect to each of these dimensions, you can form a picture of what the API looks like overall with respect to the framework. We like to create pretty graphs to do this. For example, here is a graph of an evaluation of some fictional API:
The black dotted line in the graph represents the API being evaluated. The spokes in the 'wheel' represent each of the different dimensions. End points (the middle and outer edges) on each spoke represent the end points on the scale for each dimension. Thus the point on each spoke where the black dotted line crosses it corresponds to the point on the scale for that dimension that the API has been valued at.
. . . The blue line on the graph represents the profile of a particular developer persona. For example, it shows that this persona prefers APIs that expose aggregates (the outer edge on the abstraction level scale) and APIs that have small working frameworks (the inner edge, or middle, of the working framework scale). If you compare the points where the blue lines cross each spoke with the point where the black lime crosses each spoke, you get an idea for how well the API matches the persona's ideal API. Hopefully you can see that this particular API doesn't really hit the mark for this persona (there are big differences between the points where both lines cross on most, if not all, of the spokes in the graph).