Citation

Smith K, O'Day J. Accid. Anal. Prev. 1982; 14(2): 131-133.

Copyright

(Copyright © 1982, Elsevier Publishing)

DOI

unavailable

PMID

unavailable

Abstract

Two-way tabulation of data when a third interacting variable is present can lead to false inferences. In this paper it is shown that the probability of an occupant fatality given a crash in a single-vehicle accident is independent of vehicle size in an aggregate data set. When the data set is partitioned into 2 occupant age groups, it is seen that both of the age groups have higher fatality rates in smaller cars. This is discussed as an example of a paradox presented by Simpson in his 1951 paper.