Making Sense of the Varieties of DR Approaches

There are already many different approaches to DR, and more are coming into existence on a regular basis. This multiplicity of approaches shows that the DR field is healthy, but it also creates the need to make sense of this variety by finding organizing principles. In this section, we will therefore look at some ways of characterizing DR approaches to facilitate comparison, reveal trends and highlight issues. Describing even briefly the many approaches used is beyond the scope of this chapter, but we will describe some approaches that are frequently used and others that challenge widely held assumptions. There are three ways of characterizing approaches to DR that reveal fundamental differences and similarities among them. One is to look at the way in which DR is represented and processed in an approach. Another is to describe the extent to which approaches are descriptive or prescriptive with respect to design. The third is to describe their intrusiveness in the design process.

DR representation form. Almost invariably, DR is represented by being divided up into chunks that are assigned certain properties and/or relationships. By far, the most common way of doing this is through use of a DR schema, i.e., a fixed, semi-formal, conceptual schema that represents the types of elements (chunks), properties and relationships in terms of which DR is represented. An alternative approach to DR representation involves linking DR chunks to features of the artifact they discuss. Yet another approach is to link DR chunks to steps in a description of the process of using the artifact.

−DR process implementation. Using a DR approach involves making commitments about how to implement three basic processes: o Capturing rationale, the process of eliciting rationale from designers and recording it o Formalizing rationale, the process of transforming rationale into the desired representation form, such as a DR schema o Providing access to rationale, the process of getting recorded rationale

to the people who need it A given rationale approach typically indicates how each of these processes is to be implemented. It indicates which entities perform processes.