Reliability and Validity Study
The Diagnostic Adaptive Behavior Scale (DABS) is an individually administered standardized measure of adaptive behavior. Adaptive behavior is defined as the collection of conceptual, social, and practical skills that have been learned and are performed by people in their everyday lives (Schalock et al., 2010). The DABS is composed of 75 items, broken up into the primary domains of adaptive behavior (conceptual, social, and practical skills). Typical administration time is between 20-30 minutes. The DABS was developed to be administered via interview to the parent, caregiver, teacher, or other respondent who knows the person whose adaptive behavior is being assessed. The current study entails collecting data on the reliability and validity of the DABS.
Criteria for Participation
You are qualified to be a DABS interviewer if you are a professional who has completed at least a Bachelor’s degree, has several years of direct work experience with people with an intellectual disability or related developmental disability, and has previous assessment experience (e.g., case manager, psychologist, social worker, teacher, graduate student, etc.).
The assessed individual is the person whose adaptive behavior is being rated by the DABS. Assessed individuals should be between 4 and 21 years old (inclusive), and should have an approximate IQ ranging from 55 – 80. These individuals MAY NOT serve as their own respondents (i.e. rate their own adaptive behavior) for the DABS interview. If possible, we also hope to attain historical IQ data on the assessed individual. For individuals 4-12 years old, the IQ test must have been completed within the past year. For individuals 13-21, the IQ test only needs to have been completed within the past 2 years.
The respondent providing the information for completing the DABS should know the individual very well and have had the opportunity to observe this person on a daily or weekly basis, preferably in a variety of settings, and over an extended period of time. Respondents should be adults and may be selected from family members, friends, teachers, employers/colleagues, or direct support workers. The individual whose adaptive behavior is being assessed is NOT considered an appropriate respondent (i.e., no self-report). Ratings should be based on the respondent’s direct observation and knowledge of the adaptive behavior of the individual being assessed.
There are several forms of test reliability. Generally, reliability is defined as the degree to which test scores are consistent over repeated administrations of the same instrument. A reliable test of adaptive behavior would yield consistent and stable scores over time if the same respondent were to rate the same person’s adaptive behavior on multiple times without there being any real change in the person’s actual adaptive behavior skills (test-retest reliability). A reliable test would also yield consistent scores if one interviewer interviews two different respondents rating the same individual’s adaptive behavior (inter-respondent reliability). The proposed study will assess the following types of reliability of the DABS:
- 1. Test-Retest Reliability: Test-retest measures the stability of test scores over time – assuming no actual change in skill level. This involves the repeat administration of the DABS with the SAME Interviewer & SAME Respondent after an elapsed period of time (2 – 4 weeks). DABS scores at Time 1 (DABS-test) and DABS scores at Time 2 (DABS-retest) are compared. - Time of administration: 2 – 4 weeks elapsed between DABS Time 1 (test) & DABS Time 2 (retest).
- 2. Inter-Respondent Concordance: The SAME interviewer independently interviews two DIFFERENT but equally knowledgeable respondents about the SAME assessed individual. These two assessments should be conducted no more than 10 days apart to avoid contaminating results with stability issues. Respondent 1 DABS scores (DABS-R1) and Respondent 2 DABS scores (DABS-R2) are compared
Validity is defined as the degree to which a test is able to measure what it is intended to measure. A test with good validity is analogous to a marksman hitting a bull’s-eye because the test gives accurate information about the targeted variable. One way to assess validity is by comparing obtained results on a new test with those obtained on another test that has already been accepted as valid. This form of validity is called concurrent validity. If the new test yields results that are related to the existing standard, then this provides some evidence that the new test is measuring the same construct as the other well established test (i.e., validity).
- 3. Concurrent Validity: Comparing the DABS results with an existing standard. The Vineland Adaptive Behavior Scale – 2nd Edition (Vineland - II) is a well established measure of adaptive behavior and shown to have good reliability and validity. We will compare results obtained on the DABS and Vineland-II to establish the validity of the DABS.
- Note: A recently completed Vineland-II on file (< 2 months prior to administration of DABS) may also be used in lieu of completing a new Vineland-II.
Interviewers will receive $10.00 for time spent on each DABS protocol. Respondents are eligible to receive $5 for their time to complete the DABS interview. In the case of a DABS protocol that is not completed in its entirety (e.g., all items rated), the incentive amounts will be prorated in proportion to the completeness of the DABS. We will also be sending a brief report for each interview, complete with a composite scale score, as well as subscale scores. These results should be interpreted with caution, however, as the current study is the first to examine reliability/validity of this instrument.
FOR MORE INFORMATION PLEASE CONTACT US:
Suzanne Davis - DABS Project
The Ohio State University Nisonger Center
McCampbell Hall Suite 357
1581 Dodd Drive, Columbus, OH 43210