SERVICES RESEARCH OUTREACH SURVEY(SROS) sros8.htm

This section lists types of measurement issues and describes how they were handled by the SROS project team.

"Recall decay" refers to reductions in the reporting of behaviors due to the client’s difficulty in remembering events. Generally, clients display greater reductions in the reporting of remote events, characteristics, and behaviors (i.e., those more distant in time from the date of reporting). The SROS data collection procedures were expressly designed to counter potential biases due to recall decay. SROS staff sought to minimize these sources of inaccuracy: (1) by measuring highly salient behaviors/characteristics (i.e., ones likely to be remembered), (2) by focusing on and comparing recent time periods, and (3) by asking clients to answer quantitative questions using ranges that recognize the limitations of human memory and computational abilities. For example, when clients were asked how many days per month they used drugs, they were asked to select the most appropriate answer out of the following set of intervals (the interviewers read the intervals out loud, and displayed a written "show card" as a visual aid):

Using the midpoint of each range, these answers may be used to estimate the average days of drug use for groups or subgroups. When these data are used to make comparisons between groups above a minimal size threshold (e.g., 50 or more per group), the findings have considerable statistical precision.

As recall decay is likely to be greater for events that occurred longer ago, the interviewees would be likely to remember less substance abuse and criminal behavior in the period before the SROS episode than actually occurred. Given the before/after or pretest/post-test design of SROS, recall decay would tend to show increased, not decreased, effectiveness of treatment.

This term refers to the allocation of events, characteristics, or behaviors to an earlier or later time period than the one in which they actually occurred. SROS sought to minimize telescoping by anchoring the respondent in the SROS treatment episode with the assistance of a color-coded calendar. The interviewer used substantial effort to place the interviewee within the SROS treatment episode, as well as to place that episode within the context of the events in the interviewee’s life. Then interviewees were asked about long periods of time (i.e., five year periods). As such, SROS staff designed the interview to focus clients’ attention and anchor time repeatedly on the reference period of each question and to associate the beginning and end dates of reference periods with clearly defined and usually memorable events, such as the beginning and end of the SROS treatment episode.

Previous studies of treatment show that the period immediately prior to admission generally tends to be higher in drug and alcohol use and associated criminal behaviors than earlier or later periods of the same client’s adult life; these high levels of substance use and associated problems are among the factors that induce clients to enter treatment. Therefore, lower levels of criminal activity after treatment can to some extent be described as a reversion to a baseline behavior pattern rather an effect of treatment as such.

Studies that use short baseline and post-treatment periods, such as the day or week before admission or after discharge, are especially vulnerable to these reversion effects. However, SROS uses a five year period; the longer reference period smooths out less typical behavior that takes place immediately prior to admission.

Too many response alternatives, particularly if they are not logically sequenced, may cause a respondent to forget the response alternative when the time to answer the question has arrived. To ease that issue, SROS employed, to the extent possible, show cards that present the alternatives in a logical manner. In addition, interviewers read the alternatives to the respondents, decreasing the burden on memory.

A reluctance of persons to reveal socially undesirable traits may lead to underreported events, characteristics, or behaviors. SROS attempted to minimize underreporting by carefully selecting and training interviewers in nonjudgmental but probing interviewing techniques, by carefully explaining and repeatedly emphasizing to clients the confidentiality and purposes of the data collection, by framing questions in ways that have previously been shown to elicit reporting of sensitive behavior most readily, and by relying most heavily on analysis of the types of items least subject to underreporting bias.

Finally, respondents did acknowledge a substantial amount of illegal behavior. External validity checks are described below.

SAMHSA, an agency in the Department of Health and Human Services, is the Federal Government's lead agency for improving the quality and availability of substance abuse prevention, addiction treatment, and mental health services in the United States.

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