Do design decisions depend on “dictators”?

Abstract

Design decisions often require input from multiple stakeholders or require balancing multiple design requirements. However, leading axiomatic approaches to decision-based design suggest that combining preferences across these elements is virtually guaranteed to result in irrational outcomes. This has led some to conclude that a single "dictator" is required to make design decisions. In contrast, proponents of heuristic approaches observe that aggregate decisions are frequently made in practice, and argue that this widespread usage justifies the value of these heuristics to the engineering design community. This paper demonstrates that these approaches need not be mutually exclusive. Axiomatic approaches can be informed by empirically motivated restrictions on the way that individuals can order their preferences. These restrictions are represented using "anigrafs"-structured relationships between alternatives that are represented using a graph-theoretic formalism. This formalism allows for a computational assessment of the likelihood of irrational outcomes. Simulation results show that even minimal amounts of structure can vastly reduce the likelihood of irrational outcomes at the level of the group, and that slightly stronger restrictions yield probabilities of irrational preferences that never exceed 5%. Next, an empirical case study demonstrates how anigrafs may be extracted from survey data, and a model selection technique is introduced to examine the goodness-of-fit of these anigrafs to preference data. Taken together, these results show how axiomatic consistency can be combined with empirical correspondence to determine the circumstances under which "dictators" are necessary in design decisions.

Building the tower without climbing it: Progress in engineering systems

“…These limits may be imposed by physical constraints, social norms, or cognitive factors (e.g., Ref. ).…”

“…Elsewhere, I have provided empirical and theoretical evidence that it is indeed possible to define a preference ordering at the level of the group, presuming that group members possess some minimal agreement about the structure of the design domain . Thus, participative and rational approaches need not conflict.…”

“…) independent of design outcome, whereas correspondence privileges outcomes independent of logical consistency . These approaches are typically portrayed as in conflict; however, there is evidence they need not be . Thus, there are significant opportunities for future research that explores theoretical constructs that are commensurate with both standards of rigor.…”

Assessing causal claims about complex engineered systems with quantitative data: internal, external, and construct validity

“…Although these two approaches are often portrayed as in conflict, we argue that they can, instead, complement one another. For example, Broniatowski provided empirical and computational evidence that a commonly accepted axiom of social choice only applies in engineering contexts under limited circumstances, with implications for design by groups. Relaxation of this specific axiom yielded results that were both consistent with the remaining axioms and highly predictive of subjects’ preferences over design alternatives.…”

“…Theories with construct validity are more likely to make accurate predictions. For example, Broniatowski provided empirical evidence for the necessity to incorporate novel constructs, such as decision‐makers’ mental models and depth of knowledge, neither of which had previously been used in decision‐based design.…”