Citation

Harding CM, Eiser JR, Kristiansen CM. J. Appl. Soc. Psychol. 1982; 12(3): 169-181.

Copyright

(Copyright © 1982, John Wiley and Sons)

DOI

10.1111/j.1559-1816.1982.tb00857.x

PMID

unavailable

Abstract

This study investigated how different methods of presenting mortality statistics may influence subjective impressions of the importance of a given cause of death. Subjects were 214 students from the fifth year of a comprehensive school (average age 15). Each subject rated one of six causes of death on a scale labeled "extremely minor-extremely major cause of death" before and after receiving accurate information concerning the number of deaths per annum in the United Kingdom resulting from the cause in question. This information was presented in one of five forms: (a) a statement of what proportion of all deaths resulted from the specified cause; (b) a statement of what percentage of all deaths were so caused; (c) a pie chart representing the proportion pictorially; (d) a bar chart representing the proportion pictorially; and (e) a statement of absolute number of deaths from the specified cause without information on total number of deaths from all causes combined. Analysis showed that subjects discriminated between the different causes both before and after presentation of the information but their ratings were imperfectly calibrated with actual frequencies. Also, the changes in ratings following the information depended significantly on the mode of presentation. Except when subjects were told the absolute frequency, the changes were in the direction of decrease in perceived importance. This decrease was most marked in the bar chart and pie chart conditions. The data are interpreted in relation to the literature on statistical inference processes and on judgmental contrast.