Preliminary normative data for the Hooper Visual Organization Test for a South African sample

Abstract

The Hooper Visual Organization Test (HVOT) was designed to measure an individual’s ability to organise visual stimuli and assess visual-spatial abilities and synthesis. The current investigation sought to explore the psychometric properties of the HVOT and develop normative data for South Africans who do not speak English as a first language and who received primary and secondary public education. The research design was cross-sectional and the HVOT was administered to healthy adults (n = 111) and a clinical group (n = 17) whose ages ranged between 19 and 70 years and had an education of between 6 and 22 years. The clinical group was made up of Huntington’s Disease patients (HD/HDL2). Reliability indicators (McDonald’s omega and Rasch person reliability index) were satisfactory. The HVOT fit the Rasch model well, although item locations deviated somewhat from the expected monotonic increase in item difficulties. Statistically significant differences in total scores were observed across age, education and gender groups, forming the basis of the norms presented in this paper. A few items across these groups were flagged for potential differential item functioning. Several statistically significant associations with the Montreal Cognitive Assessment (MOCA) were observed. These were consistent with theoretical expectations and provided evidence of convergent validity. The clinical group performed worse than the control group when mean total HVOT scores were compared. Preliminary norms stratified by age, gender and years of education are presented. Future studies should include larger sample sizes and additional research on the influence of gender on the total HVOT score is needed.