Development and justification

In 1998, Visio management set up a project group to develop an instrument for observing the tactual functioning of children aged 0 to16 years who have a severe congenital visual disorder. The project group consisted of staff engaged in rehabilitation and education. They worked with other Dutch experts and specialists in the field of touch and consulted with staff of the Remedial Education departments of ‘Learning and Development’ and ‘Developmental Psychology’ at the University of Nijmegen. In 2000, this collaboration resulted in the first experimental version of Tactual Profile.

In 2001, the first version was subjected to a validation test by Dr R. Schellingerhout. The main aims were to validate the content of Tactual Profile and to carry out a process evaluation of the instrument.

The main positive conclusions were: Tactual Profile is a useful instrument that promotes expertise; the instrument generates spontaneous ideas for intervention.

The main negative conclusions were: the instrument’s large number of subject areas; s a result of this, a long test duration, especially with the 6 to 12 age group. On the basis of the research findings, this group was split into two age groups: 6 to 9 and 9 to 12.

Follow-up
The recommended follow-up was more research to collect more data and to determine ‘simple’ psychometric requirements. It was noted that ‘the Dutch research population is too small to establish reliable and valid psychometric requirements’. So in this context the requirements were referred to as ‘basic psychometric requirements’. The research was conducted in consultation with a methodology expert.

On the basis of the recommended follow-up, a request was submitted to the InSight Foundation (Stichting InZicht) of the Netherlands Organisation for Health Research and Development (ZonMW). The request was granted and the study, led by N. Janssen, was launched in September 2002.
The main aim of the study was to determine the basic psychometric qualities of the current version of Tactual Profile:

• test/retest reliability
• internal consistency
• inter-rater reliability
• construct validity.

The research population consisted of 55 Dutch and Flemish (Belgium) children aged from 0 to 16 years who had a severe congenital visual impairment but no other apparent impairments. All the centres for the visually impaired in the Netherlands and Flanders participated in the study.

Reliable
The findings show that Tactual Profile is a reliable instrument, that it can be scored reasonably reliably by different test administrators, and that it differentiates itself from intelligence tests. For further information contact Visio (see contact details under Contact) or go to the Stichting InZicht website.

DVD fragment Tactual Profile - category Touch sensitivity in several age groups.