Quantitative and ordinal attributes

In discussion of what the OSB map should include, two quantitative attributes were mentioned:

• Incline (e.g., slope of a path or lawn)
• Width of a sidewalk

Incline is the most interesting of these, because unlike the width of a sidewalk (which would be at least represented by width of an area in the map display), we currently don't have a way to represent incline at all. Note that it is distinct from, and perhaps orthogonal to, the kind of object — a sidewalk can have an incline, and a lawn can also have an incline. Moreover, incline is relative and directional: We care about grade, not altitude, and the same location can be inclined upward, downward, or level depending on which direction one is walking.

In tactile maps, there are symbols indicating incline.

The current soundscape map system has no provision for such attributes, nor is there a way to describe them in the style sheet language. My first thought is that we probably need ways of modulating existing sound cues (e.g., altering pitch) in a way that maintains the meaning of the cue ("this is a sidewalk") and conveys additional information. It might be ok to discretize quantitative attributes, for example representing incline only by one of the discrete categories "steep down", "down", "level", "up", "steep up".

We don't absolutely have to come up with ways of handling such attributes this term, but it's on the "wish list" for things that you may consider if it fits in your development schedule. As I said in class Wednesday, your project should be structured as a sequence of increments, so that the question is not when you are done but rather what you get done. (This is a very common approach to system design and project planning when deadlines are inflexible.)