Citation

Ceder A, Dressler O. Accid. Anal. Prev. 1980; 12(1): 7-10.

Copyright

(Copyright © 1980, Elsevier Publishing)

DOI

unavailable

PMID

unavailable

Abstract

The routine use of the chi-square tests has perhaps led to an incorrect consideration of basic underlying data in two articles in the accident and transportation fields. This paper emphasizes the necessity of comparing actual measured (observed, resultant, etc.) units with those which are expected. The two detected errors found in the literature serve as a warning stimulus in using proportions or transformed units instead of the actual numbers in chi-square tests. Several examples of data preparation are exhibited in detail. In addition, road accidents in construction or maintenance zones are analyzed as an application of correct usage of the basic available data.