Addictive Behaviors, Val. II, pp. 149-161, 1986 Printed in the USA. All rights reserved. 0306-4603/86 $3.00 + .00 Copyright c 1986 Pergamon Journals Ltd THE RELIABILITY OF A TIMELINE METHOI) FOR ASSESSING NORMAL DRINKER COLLEGE STUDENTS' RECENT DRINKING HISTORY: UTILITY FOR ALCOHOL RESEARCH MARK B. SOBELL, LINDA C. SOBELL, and FELIX KLAJNER Addiction Research Foundation and University of Toronto, Ontario, Canada DANIEL PA V AN University of Toronto ELLEN BASIAN New York University Abstract... The test-retest reliability of male (n = 40) and female (n = 40) college students' reports of recent drinking behavior was evaluated using a timeline (TL) procedure. The students also completed a quantity-frequency (QF) questionnaire (Cahalan, Cisin, & Crossley, 1969) often used to categorize subjects' drinking histories in alcohol research studies. The TL- derived data were found to have generally high n:liability (usually ,'s ~ .87) for both males and females, with males having slightly higher reliabilities overall. Subjects were classified into drinker categories based on the QF questionnaire answers, and the resulting groups were com- pared using their TL-derived data on quantity, frequency, and quantity X frequency (mean number of drinks per drinking day) measures of drinking. The drinking behavior of subjects (as assessedby the TL) had great variability within the QF categories, and there was extensive overlap between subjects t;lassified by the QF method as heavy, moderate and light drinkers. Thus, QF categorization provides a relatively insensitive measure of individual differences in drinking behavior as compared to TL-derived data. The TL method also can be used to gener- ate a variety of potentially useful dependent variables, whereas the QF method generates a sin- gle variable. Acquired tolerance to alcohol, the decrease in the effect of a given dose 'Jf alcohol on an individual as a function of drinking experience, is an important determinant of how an individual is affected by alcohol (Cappell & LeBlanc, 1981). Thus, in experimental alcohol research, acquired tolerance is likely to be a mediator of experimental effects. Although it often is not possible to obtain an independent assessment of tolerance levels (e.g., due to ethical considerations, equipment limitations), subjects' reports of their recent drinking behavior may provide a useful, if rough, estimate of their levels of tolerance. However, the literature on experimental alcohol studies with humans in- cludes relatively few studies where recent drinking history has been used as a variable (see Adesso, 1980, and Marlatt & Rohsenow, 1980, for partial reviews of this litera- ture). When such studies have been conducted, recent drinking history has most often been used as a between-subjects variable where subjects are assigned to groups (e.g., light drinkers, heavy drinkers) based on their drinking practices (e.g., Wilson, Abrams, & Lipscomb, 1980; Steele, Southwick, & Critchlow, 1981), although occasionally the effects of recent drinking history have been investigated using correlational or regres- sion techniques (e.g., Brown & Cutter, 197~'). The authors gratefully acknowledge the assistance of Reinhard 5chuller in the computer analysis of data. The views expressed in this publication are those of the aluthors and do not necessarily reflect those of the Ad- diction Research Foundation. Requests for reprints should be sent to Mark B. 5obell, Clinical Institute, Addiction Research Foundation, 33 Russell 5t., Toronto, Ontario, Canada, MS5 251. 149