Reliability is a word you will see used often in AAIDD SIS training programs. Simply stated, reliability means consistency—that is, results obtained by the persons trained to administer the instrument would be consistent with the results obtained by the developers of the Scale, respecting its original intent in measuring the support needs of an individual. Once reliability is established, any trained interviewer who administers the tool will obtain comparable results (plus or minus an acceptable error rate). This is especially true in situations where multiple people are needed to assess large numbers of individuals. In these instances, establishing the inter-rater reliability of each interviewer becomes essential to the overall interview process. The more people trained to administer the Supports Intensity Scale, the more clear the strategies are for assessing the inter-rater reliability of those individuals. Only in this way can the integrity of the data obtained from SIS assessments be assured, and by doing so, resources and services to people with intellectual disability are allocated in a fair and accurate manner.
Read more about reliability:
2011 Validity and Reliability Results Regarding the SIS