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Validation of the Tactual Profile

Focus: School Years

Topic: Assessment

Ans Withagen

Remedial educationalist

Visio institute for the visually impaired

Amersfoortsestraatweg 180

Huizen

The Netherlands

+31 35 6985811

answithagen@visio.nu

Roelof Schellingerhout

Senior researcher

Social and Cultural Planning Agency

Parnassusplein 5

Den Haag

The Netherlands

+ 31 70-3417812

r.schellingerhout@scp.nl

1. Introduction

The Tactual Profile aims to measure the tactile prerequisites of activities of daily living and school-related subjects in legally blind children up to 16 years of age with no additional disabilities. The Tactual Profile was developed by Visio, a Dutch institute for the visually impaired. The Tactual Profile was proposed by practitioners working with visually impaired children, e.g., remedial educationalists, early interventionists, physiotherapists, and remedial teachers. The outcomes of an assessment with the Tactual Profile may be used as a basis for interventions.

The Tactual Profile consists of items, arranged on the basis of a facet-analysis, according to age–level (the originally proposed age-levels were 0-2; 2-4; 4-6; 6-12; and 12-16 years of age) and tactual domain (practical skills, sensor aspects, motor aspects and perceptual aspects of tactual functioning). Further, the Tactual Profile comes with a set of materials, to be used in the administration of the items. These materials consist of tangible graphics and other materials, such as tactual puzzles. In addition to these standardised materials, other common household or school related materials have to be used in an administration of the Tactual Profile.

2. The validation study

2.1 Goals

In the year 2001, a validation study on the tactual profile was carried out.

The goals of this validation study were:

(1)   Content-validation of the Tactual Profile. This goal involved the following questions. Do the items of the Tactual Profile measure what they intend to measure? Are there any missing items? Is the arrangement of the items across different age-levels and tactual domains in accordance with the opinions of practitioners, experts and our knowledge on touch?

(2)   A process-evaluation of the Tactual Profile, aimed at the practical use of the instrument. This goal involved the ease-of-use of the instrument, the quality of the materials and the proposed manner of administration, the load of an administration for the administrator and the child. This goal also involves the experiences of the administrators. How useful is the Tactual Profile in their everyday work with visually impaired children and do they think it is important to chart the tactual development of visually impaired children.

2.2 Method

Two series of trial administrations of the Tactual Profile were carried out. The administrators all were practitioners, professionals working with visually impaired children. The administrators received a one day training programme, in which they were instructed in the administration of the Tactual Profile.

In the first series of trial administrations, 10  children (two for each of the five age-levels) received an administration of the Tactual Profile. By means of evaluation-forms, every item was rated on a large number of aspects, e.g., its formulation, usefulness, ease of administration, difficulty and tactual domain. In addition to this evaluation-form, every administrator was interviewed according to his or her experiences with the Tactual Profile. The outcomes of the evaluation forms and interviews led to a first adjustment of the Tactual Profile, which was further tested in the second series of trial administration.

In the second series of trial administrations of the Tactual Profile, a larger group of children (27 in total) received an administration of the Tactual Profile. Items were evaluated in a similar way as in the first series of trial administrations. In addition, the items of the adjusted version were evaluated by a group of four special educationalists. The outcomes of these evaluations led to a second adjustment of the Tactual Profile.

2.3 Results: the adjustments to the Tactual Profile.

The most important outcome of both series of trial administrations was that the administrators and special educationalists rated the Tactual Profile as an important and useful instrument. E.g., the administrators indicated that the Tactual Profile gave them ideas and leads for interventions with the children. In addition, the Tactual Profile furthers approaching the sense of touch in a more structured way.

The most often mentioned drawback of the Tactual Profile was it’s length. A total administration time of 4-5 hours for the older children (6 years and up)was not uncommon.

 

Table 1 gives an overview of the adjustments made to the Tactual Profile on the basis of the two series of trial administrations.

Table 1. Overview of the adjustments to the Tactual Profile.


Adjustment


 

Trial administration series 1

 

Trial administration series 2

 

Formulation of items

 

+

 

-

 

Removal of items

 

+

 

+

 

Addition of items

 

+

 

-

 

Placement of items across tactual domains

 

+

 

+

 

Removal of tactual domains

 

+

 

-

 

Placement of items across age-levels*

 

+

 

+

 

Manner of administration and administration forms

 

+

 

+

 

Guide questions

 

+

 

+

 

Cross-references of similar items

 

+

 

+

 

Tangible graphics and other materials

 

+

 

+

 

Differentiation of the 6-12 years age level

 

-

 

+

 

Alert signals (indicating possible areas of tactual development at risk)

 

-

 

+

 

Screening of visual functioning

 

-

 

+

 

Texts of the manual

 

-

 

+

 

A “+” indicates adjustment, a “-” indicates no adjustment.

*Series 1: based on the ratings of the administrators, series 2: bases on the actual administrations themselves (+ratings of the administrators and special educationalists).

The most important adjustments to the Tactual Profile from the original version to the final adjustment were:

(1)   The addition of guide-questions. These guide-questions contain examples how to formulate a certain item for the child or specific instructions for the administration. These guide-questions promote the standardised administration of the Tactual Profile.

(2)     The differentiation of the original 6-12 year age level into two separate age levels: 6-9 years of age and 9-12 years of age. This differentiation was made on the basis of the actual data of the second series of trial administrations. This differentiation will reduce the administration time of the Tactual Profile.

(3)     The placement of items across age-levels. On the basis the data of the actual administrations of the second series, the items were placed in order of difficulty. Difficulty here refers to the number of children that pass a certain item. As was to be expected, there was a large correlation between numbers of item passed and age This order of the items is provisional and needs to be adjusted in the future as more and more children receive administrations of the Tactual profile. As more experience with the Tactual Profile is gained, a possible shortened version may become possible.

(4)     The addition of a screening of a child’s visual functioning. If a child has any functioning visual capabilities, this will influence the administration of the Tactual Profile to a large extent. To control for this possibility a screening was added to the instrument.

3. Conclusion and Discussion

The Tactual Profile is a useful instrument which gives practitioners leads for interventions and furthers a structured way of thinking about the sense of touch.

The next step in the development of the Tactual Profile as an assessment instrument is the further determination of basis psychometric properties. This will be the focus of future investigations, which are already in the planning stage.


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