RELIABILITY AND VALIDITY OF THE DATA AND MEASURES FROM TWO NATIONAL SURVEYS OF ADOLESCENT DRINKING

R e l i a b i l i t y and v a l i d i t y are basic issues in any type of research and are especia l ly important to the study of the a t t i tudes , motivations and behaviors of adolescents in areas such as alcohol use, drug use and deviant behavior. The fundamental issues of r e l i a b i l i t y and v a l i d i t y may be more d i f f i c u l t to examine in studies of adolescents. The usual problems of reca l l , recognit ion and report ing could be compounded by a number of factors more charac ter is t i c of adolescent than adult experience such as peer pressure, rap id ly changing a t t i tudes, maturation, exposure to new experiences and parental sanctions. The subject area of reports, the context in which the reports were obtained and the point of the respondent in the developmental process are some of the confounding issues that might a f fec t in terpretat ions of the r e l i a b i l i t y and v a l i d i t y of the data. Despite these problems, evidence of r e l i a b i l i t y and v a l i d i t y is avai lable. In studies of drug use among high school students, Haberman et al. (1972) found adequate levels of internal consistency. Mayer and Fi lstead (1979) found high tes t re tes t r e l i a b i l i t i e s of a measure of alcohol involvement for adolescents. Johnston (1973) reports that the drug use questions in his survey of high school students had a nonresponse rate of less than two percent, even though respondents were spec i f i ca l l y instructed not to answer questions that made them uncomfortable or would force them to misrepresent themselves to the in te r viewer. Length of recal l also has been found to a f fec t reports of prevalence (Uppal, Babst, and Schmeidler, (1977). Although the use of construct va l ida t ion procedures in alcohol research among high school students has been l imi ted. Kandel (1975), Jessor and Jessor (1978) and Johnston (1973) argue that the patterns of re lat ionships among alcohol and drug use and other behaviors are consistent with current theories of substance abuse. Attempts have been made to compare se l f repor ted use with perceptions of f r iends' use. In one study 63 percent of adolescents whose best fr iends were drug users reported drug use compared to 22 percent of those whose best fr iends were nonusers (Single, Kandel, and Johnson, 1975). Users have been found to d i f f e r from non-users on a number of variables not d i r ec t l y connected to drug use including absenteeism (Single, Kandel, and Johnson, 1975), poor school performance, de l inquency, and countercul tural l i f e s t y l e (Johnston, 1974). No studies have attempted to ve r i f y reports of adolescent alcohol use with chemical tests , record searches or proxy reports. This paper discusses the examination of the v a l i d i t y and r e l i a b i l i t y of the data in the 1974 and 1978 surveys of adolescent dr inking conducted by RTI and the construct v a l i d i t y of indices of alcohol use and misuse developed for the study. The context for th is discussion involves the potent ia l problems in obtaining re l i ab le , va l id and useful data from adolescents concerning behaviors usually considered deviant by society.