abstract = "Market researchers often conduct surveys to measure
how much value consumers place on the various features
of a product. The resulting data should enable managers
to combine these utility values in different ways to
predict the market share of a product with a new
configuration of features. Researchers assess the
accuracy of these choice models by measuring the extent
to which the summed utilities can predict actual market
shares when respondents choose from sets of complete
products. The current paper includes data from 201
consumers who gave ratings to 18 cell phone features
and then ranked eight complete cell phones. A simple
summing of the utility values predicted the correct
product on the ranking task for 22.8 percent of
respondents. Another accuracy measurement is to compare
the market shares for each product using the ranking
task and the estimated market shares based on summed
utilities. This produced a mean absolute difference
between ranked and estimated market shares of 7.8
percent. The current paper applied two broad strategies
to improve these prediction methods. Various
evolutionary search methods were used to classify the
data for each respondent to predict one of eight
discrete choices. The fitness measure of the
classification approach seeks to reduce the
Classification Error Percent (CEP) which minimizes the
percent of incorrect classifications. This produced a
significantly better fit with the hit rate rising from
22.8 to 35.8 percent. The mean absolute deviation
between actual and estimated market shares declined
from 7.8 to 6.1 percent (p. <0.01). A simple language
specification will be illustrated to define symbolic
regression and classification searches.",