Table 4 Selective coding schema for characteristics and invariants of a design problem

 1. Ambiguous specification of goals

-The goal for the set out task is lacking in specificity, it is ill-defined, vague, and left open for interpretation. Proper evaluation metrics cannot be used to determine how appropriate a given solution is for the problem in large part because of the uncertainty of what the goal truly is.

 2. No known solution path

-Given the ambiguity of the goal, there is no definite set of actions a designer can or should take to reach that goal. There is no map to follow and essentially one must create the pathway prior to and while walking it, which in turn creates unfamiliarity and discomfort.

Design problem invariant

Indicator descriptor

 1. Design problem structuring

-The starting point for designers lacks information and definitive goals; therefore, purposeful structuring of the problem needs to occur. This results in a set of specific actions as designers look for pertinent information and attempt to structure their task in a way that is comprehensible at the point in time that it was conceptualized.

 2. Modularity/decomposability

-The complexity and size of a design problem inherently forces designers to compartmentalize it into “modules.” Because presupposed connections amongst the modules are contingent, designers will likely attend to some and ignore others. Also, as contingent connections invariably change, some modules are thereby ignored or lost all together.

 3. Distinct problem-solving phases

-Designers will exhibit distinct behaviors and actions during each of the three phases of problem solving: preliminary, refinement, and detailed design. As a result, certain requirements are created that must be attended to during each phase, including but not limited to the amount of attention given to detail.

 4. Incremental development of an artifact

-Provisional ideas that are discovered are incrementally nurtured by designers and rarely completely abandoned because there are no right or wrong answers to the problem. It is therefore permissible and acceptable to hold on to a given idea, which may eventually become a suitable artifact while it is steadily developed.

 5. Personalized stopping rules and evaluation functions

-Evaluating any proposed idea or choice requires that designers make personalized evaluations because one can never know for sure what the “right” answer is. As a result, designers tend to institute experienced-based “rules” or strategies that allow them to move forward.