Editorial

This special issue on Adapting developmental assessment instruments for children with special needs contains three articles describing studies about assessment in target groups for which test validity is not self-evident.

In the paper Assessment of verbal comprehension and non-verbal reasoning when standard response mode is challenging: a comparison of different response modes and an exploration of their clinical usefulness, Kurmanaviciute et al. describe a study into the assessment of verbal comprehension and visuospatial abilities in children with cerebral palsy. To give in to the severe speech and motor impairments of these children, they developed alternatives for the standard response mode (finger pointing): gaze pointing and partner assisted scanning. In typically developing children, the type of response mode did not influence the test outcome, which means that they are interchangeable. The alternative response modes appeared to make it possible to obtain meaningful information about cognitive functioning in children with cerebral palsy. The authors discuss factors to take into account when choosing between the two alternative response modes.

In Assessment in people with PIMD: Pilot study into the usability and content validity of the Inventory of the Personal Profile and Support, Wessels et al. describe a study into an assessment that can be used to develop a personal profile of people with profound intellectual and multiple disabilities (PIMD). This target group is characterised by a profound intellectual disability, combined with severe motor disabilities as well as sensory impairments. The Inventory of the Personal profile and Support (IPS) has been developed just for this target group as a basis for developing individualised support. The study results show that the general usability and the content validity of the IPS can be rated as good.

The study described in Assessment of temperament in children with profound intellectual and multiple disabilities – A pilot study into the role of motor disabilities in instruments to measure temperament (Van der Putten et al.) focuses on young children with PIMD. The research question was: how can we measure temperament in this target group? Temperament is an important factor to take into account in developing individualised support, but the impairments related to PIMD could influence the validity of temperament assessments. The results show that the Infant Behavior Questionnaire-Revised (IBQ-R) very short form and the Child Behavior Questionnaire (CBQ) very short form seem to be most appropriate, but need to be accommodated to increase the suitability for the target group. The paper includes accommodation suggestions.

The three studies all point at the necessity to accommodate the assessment depending on the individual needs of a child. Several characteristics of the child thereby need to be taken into account, like motor impairments, sensory impairments (visual, auditory), as well as fatigability. The three studies also all highlight the importance of assessment for developing individualised support. By preventing impairments in one area influencing test outcomes about a different area of development, test validity increases and underestimation of the developmental level and skills of a child can be prevented.

The relation between the assessment of different areas of psychological development and the impaired area of development influencing the test validity has been visualised in the following matrix:

Table

		Assessment
		Cognition	Language	Motor skills	Social-emotional development
Impairment	Cognition		Wessels et al.	Wessels et al.	Wessels et al.; Van der Putten et al.
	Language	Wessels et al.		Wessels et al.	Wessels et al.; Van der Putten et al.
	Motor skills	Wessels et al.; Kurmanaviciute et al.	Wessels et al.; Kurmanaviciute et al.		Wessels et al.; Van der Putten et al.
	Social-emotional development	Wessels et al.	Wessels et al.	Wessels et al.
	Sensory abilities (hearing, vision)	Wessels et al.	Wessels et al.	Wessels et al.	Wessels et al.; Van der Putten et al.

The papers in the current special issue can be categorised in this matrix: the study of Kurmanaviciute et al. deals with assessing the cognition and language (more specifically, non-verbal reasoning and verbal comprehension, respectively). The paper by Van der Putten et al. deals with assessing temperament, which can be categorised under the broader category of social-emotional development, in children with PIMD, who have impairments in the various developmental areas. The paper by Wessels et al. focuses on the same target group and on a broader assessment, namely the construction of a personal profile. In a personal profile, the various areas of development are represented. Therefore, the article by Wessels et al. can be categorised in each of the white cells in the matrix.

The idea for this matrix, and more broadly for this special issue, comes from Prof.. dr. B.F. van der Meulen, who sadly passed away in 2016. It has originated from the research work he has conducted at the department of special needs education, University of Groningen. This focused on the developmental assessment of young children, and in more recent years on test validity when assessing young children with special needs. In one of the most recent projects he was involved in, together with Dr. S.A.J. Ruiter, Prof. Dr. M.E. Timmerman, Prof. Dr. A.J.J.M. Ruijssenaars, and me, a Special Needs Addition was developed and studied for an important developmental assessment instrument (the Bayley-III). There is increasing interest in this accommodated instrument, internationally and from both researchers and practitioners, which yields applications in daily practice as well as new research projects to further develop assessment possibilities. The work of Professor van der Meulen is thus being continued.

Professor van der Meulen has played an important role in the development of this special issue and this editorial has been written also on behalf of him.

I would like to conclude this editorial by thanking the authors for submitting their work to this special issue of Cogent Psychology. Together, the papers give an overview about the work that is currently being done on the assessment of children with special needs. The special issue can also form a starting point for directing future research. For example, there are many target groups, other than those described in this special issue, for which there is a need for more suitable and valid assessment instruments. Examples are people with specific sensory impairments such as deafblindness, with a specific syndrome such as Angelman Syndrome, or with psychiatric problems such as autism spectrum disorder. Accommodated instruments, in combination with and an evidence-based guideline to accommodating assessments to individual needs, would yield more valid assessments, more valid information about the development or skills of a person, and hence better possibilities for individualised and effective support.