### abstract ###
i show how the coherence correspondence distinction can inform the conversation about decision methods for engineering design
some engineers argue for the application of multi-attribute utility theory while others argue for what they call heuristics
to clarify the differences among methods  i first ask whether each method aims at achieving coherence or correspondence
by analyzing statements in the design literature  i argue that utility theory aims at achieving coherence and heuristics aim at achieving correspondence
second  i ask if achieving coherence always implies achieving correspondence
it is important to provide an answer because while in design the objective is correspondence  it is difficult to assess it  and coherence that is easier to assess is used as a surrogate
i argue that coherence does not always imply correspondence in design and that this is also the case in problems studied in judgment and decision-making research
uncovering the conditions under which coherence implies  or does not imply  correspondence is a topic where engineering design and judgment and decision-making research might connect
### introduction ###
kenneth hammond  CITATION  has pointed out that a method can be evaluated both according to its internal consistency  or coherence  and its external performance  or correspondence
it is important to keep this distinction in mind when comparing decision methods because one method could be achieving coherence while another method could be achieving correspondence
for example  the take-the-best heuristic  CITATION  violates a criterion of coherence transitivity that is satisfied by linear regression  while  under some conditions  take-the-best outperforms regression in a criterion of correspondence predictive accuracy
in this article  i show how the coherence correspondence distinction can inform the conversation about decision methods within a field that has had minimal overlap with jdm judgment and decision making  the field of engineering design
in  NUMBER   national science foundation nsf engineering design program director george hazelrigg wrote   it is increasingly recognized that engineering design  is a  decision-intensive process  p  NUMBER 
the nsf has  since  NUMBER   sponsored numerous workshops on decision-based design
the accreditation board for engineering and technology also defines engineering design as a decision-making process
what decisions do design engineers make
design engineers choose among alternative concepts
a design concept is a technical specification of an artifact that is detailed enough so that the engineer can predict  reasonably accurately  how the artifact will function
for example  a concept of a chair would specify the material used to build each chair part and the geometrical relationships among the parts
there are typically many attributes on which design concepts can be evaluated
examples of attributes for a chair concept are durability  comfort  or production cost
hereafter  i refer to design concepts as simply designs
some engineers  CITATION  argue for the application of multi-attribute utility theory for choosing among designs  while others argue for what they call heuristics  such as stuart pugh's convergence process  CITATION
this debate has by and large ignored the coherence correspondence distinction
i ask two questions that use the distinction and inform the debate
the first question is whether each method aims at achieving coherence or correspondence or both
by analyzing published statements in the design literature  i argue that multi-attribute utility theory aims at achieving coherence while the pugh convergence process aims at achieving correspondence
the second question is if achieving coherence always implies achieving correspondence
it is important to answer because while in design the objective of decision-making is correspondence  it is difficult to assess it  and coherence that is easier to assess is used as a surrogate
for the surrogate coherence to be useful for inferring the objective correspondence  the relationship between the two must be known
i argue that coherence does not always imply correspondence in design  and that this is also the case in decision problems studied in jdm
i conclude that the study of conditions under which coherence implies  or does not imply  correspondence is a topic where design and jdm research might connect
before asking and answering the two questions  i review two methods for making decisions that have a prominent place in engineering design theory and practice
