The Hayes Ability Screening Index-Nonverbal (HASI-NV) is a brief, individually administered screening index of intellectual abilities. The HASI-NV is intended for use with people aged between 13 and late adulthood. It was developed primarily to provide a short and effective instrument to indicate the possible presence of intellectual disability amongst persons in contact with the justice system and to determine those who need to be referred for further full-scale diagnostic assessment. In police settings, the HASI-NV is designed to identify those accused persons who may be vulnerable during detention or police interviews, so that appropriate provisions (including presence of an independent third party) for vulnerable interviewees may be implemented.
The HASI-NV follows on from the Hayes Ability Screening Index (HASI) (Hayes, 2000) which was developed in response to difficulties experienced by professionals in the criminal justice system in recognising the presence of intellectual disabilities. As the HASI began to be used in non-English speaking environments and in jurisdictions that did not have welfare and educational provisions similar to those existing in Australia and other Western nations, it became apparent that some items and sub-tests were not universally appropriate. The HASI was translated into other languages, including Dutch, Norwegian, and French Canadian, but the translation process was difficult owing to verbally based items such as being able to spell a word backwards, or translating questions about welfare benefits or special education. Hence, it was clear that there was a need for a screening test which was minimally dependent upon verbal or literacy skills, and did not refer to support systems for people with intellectual disabilities such as welfare payments and special education.
The HASI-NV has been designed for use by professionals working at every stage of the justice system, especially the criminal justice system, as well as in mental health and other community settings. Provided appropriate training in the administration and scoring of the test has been undertaken, non-psychologists can administer the Index. The test is useful to police, solicitors and barristers, probation and parole personnel, juvenile justice workers, justice health professionals, corrective services staff, drug and alcohol counsellors, forensic, community and correctional mental health professionals, and service providers in other community settings such as health care, supported housing and immigration. The HASI-NV is brief, and easy to administer and score. The Manual includes instructions for administration of the Index, scoring criteria, and test development and validation data. The final score on the HASI-NV indicates whether the person tested should be referred for further full-scale psychological assessment of intellectual and adaptive behaviour functioning. They may be referred also for psychiatric or other assessments. In police settings, the score indicates that special provisions for vulnerable interviewees may need to be implemented, to ensure their safe detention, respect their rights during interviews, and allow for the presence of and support from an independent third party during police interviews.
The HASI-NV itself is not an instrument suitable for making a diagnosis of intellectual disability or any other mental abnormality. The Index is suitable only for indicating which test takers should be referred for further psychological, psychiatric or other diagnostic assessment, or should have special provisions implemented during police interviews or detention.