Construct Validity of the Three Motor-Reduced Subscales of the Developmental Test of Visual Perception - Adolescent and Adult (DTVP-A): A Rasch Analysis Model Evaluation

By Brown, Ted | British Journal of Occupational Therapy, February 2011 | Go to article overview

Construct Validity of the Three Motor-Reduced Subscales of the Developmental Test of Visual Perception - Adolescent and Adult (DTVP-A): A Rasch Analysis Model Evaluation


Brown, Ted, British Journal of Occupational Therapy


Introduction

Visual perception constitutes the ability to identify, organise and prescribe meaning to the visual information received through the eyes (Hammill et al 1993, Scheiman 1997a, Grieve and Gnanasekaran 2008). This metaskill has been acknowledged to be closely aligned with complex cognitive operations that contextualise raw visual information in terms of one's pre-existing environmental views and other sensory experiences (Bouska et al 1990, Hendee 1997, Grieve and Gnanasekaran 2008). Visual perception is an essential aspect of one's abilty to 'mentally manipulate visual information as needed to solve problems' and 'take action in response to environmental demands' (Kurtz 2006, p33). This, in turn, promotes a person's overall functional performance capacity and allows him or her safely and independently to perform self-care tasks and participate in work or leisure-related activities (Erhardt and Duckman 1997, Scheiman 1997a, Cooke et al 2006, American Occupational Therapy Association [AOTA] 2008). Unfortunately, however, the complexity of the human visual perceptual system renders it 'vulnerable to many dysfunctional skills which can severly impact its effectiveness as an information processing tool' (Su et al 1995, p3).

As a consequence, therapists regularly assess visual perception, particularly when working with clients who present with pre-existing diagnoses commonly associated with visual perceptual problems (Zoltan 1996, Golisz and Toglia 2003, Phipps 2006, AOTA 2008, Brown and Rodger 2009). Diagnoses often presenting with visual perceptual dysfunction include multiple sclerosis, dementia, Parkinson's disease, cerebrovascular accident, brain tumour and acquired brain injury (Bouska et al 1990, Cockburn et al 1990, Neistadt 1990, Ogden et al 1990, Edmans et al 1991, York and Cermak 1995, Vleugels et al 2000, Mercier et al 2001, Glosser et al 2002, Kozeis et al 2007).

One visual perceptual test used by therapists to assess adult visual perception is the Developmental Test of Visual Perception--Adolescent and Adult (DTVP-A) (Reynolds et al 2002). The DTVP-A was developed and standardised in the United States and emerged from a revision and extension of the Developmental Test of Visual Perception 2nd edition (DTVP-2) (Hammill et al 1993). As noted in its manual, the 'DTVP-A is presented as, in essence, an age extension of the DTVP-2' (Reynolds et al 2002, p v). Given that health care professionals outside the United States often use the DTVP-A to assess the visual perception of adult-age clients, it is important to explore its validity when used in cross-cultural contexts (Leverett 2005, Brown et al 2008).

Current measurement theory argues that the development of instruments must begin with establishing their construct validity; that is, assessing how well the items of instruments, collectively and individually, capture a single cohesive theoretical concept that they seek to measure. In other words, the validity of an instrument rests on the ability of its items to reflect an underlying construct (Nunnally and Bernstein 1994). According to Rasch theorists, empirical validation of test quality requires (at least) that the items of an instrument exhibit four properties: (1) potential to yield interval level scaling (scalability); (2) unidimensionality; (3) lack of differential item functioning across different subjects and test occasions; and (4) hierarchical ordering (Doble and Fisher 1998). 'When these properties are demonstrated, then the items act together as a "ruler", indicating amounts of the construct that the scale seeks to measure' (Mallinson et al 1998, p222). This study, therefore, addresses this issue by assessing the construct validity of the DTVP-A's three motor-free subscales using the Rasch analysis model in an Australian setting (Bond and Fox 2007).

Literature review

Construct validity

In the past, validity was defined as three separate types: content, criterion and construct, with criterion-related validity subdivided into concurrent and predictive validity (Nunnally and Bernstein 1994, Anastasi and Urbina 1997). …

The rest of this article is only available to active members of Questia

Already a member? Log in now.

Notes for this article

Add a new note
If you are trying to select text to create highlights or citations, remember that you must now click or tap on the first word, and then click or tap on the last word.
One moment ...
Default project is now your active project.
Project items

Items saved from this article

This article has been saved
Highlights (0)
Some of your highlights are legacy items.

Highlights saved before July 30, 2012 will not be displayed on their respective source pages.

You can easily re-create the highlights by opening the book page or article, selecting the text, and clicking “Highlight.”

Citations (0)
Some of your citations are legacy items.

Any citation created before July 30, 2012 will labeled as a “Cited page.” New citations will be saved as cited passages, pages or articles.

We also added the ability to view new citations from your projects or the book or article where you created them.

Notes (0)
Bookmarks (0)

You have no saved items from this article

Project items include:
  • Saved book/article
  • Highlights
  • Quotes/citations
  • Notes
  • Bookmarks
Notes
Cite this article

Cited article

Style
Citations are available only to our active members.
Buy instant access to cite pages or passages in MLA, APA and Chicago citation styles.

(Einhorn, 1992, p. 25)

(Einhorn 25)

1. Lois J. Einhorn, Abraham Lincoln, the Orator: Penetrating the Lincoln Legend (Westport, CT: Greenwood Press, 1992), 25, http://www.questia.com/read/27419298.

Cited article

Construct Validity of the Three Motor-Reduced Subscales of the Developmental Test of Visual Perception - Adolescent and Adult (DTVP-A): A Rasch Analysis Model Evaluation
Settings

Settings

Typeface
Text size Smaller Larger Reset View mode
Search within

Search within this article

Look up

Look up a word

  • Dictionary
  • Thesaurus
Please submit a word or phrase above.
Print this page

Print this page

Why can't I print more than one page at a time?

Help
Full screen

matching results for page

    Questia reader help

    How to highlight and cite specific passages

    1. Click or tap the first word you want to select.
    2. Click or tap the last word you want to select, and you’ll see everything in between get selected.
    3. You’ll then get a menu of options like creating a highlight or a citation from that passage of text.

    OK, got it!

    Cited passage

    Style
    Citations are available only to our active members.
    Buy instant access to cite pages or passages in MLA, APA and Chicago citation styles.

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn, 1992, p. 25).

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn 25)

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences."1

    1. Lois J. Einhorn, Abraham Lincoln, the Orator: Penetrating the Lincoln Legend (Westport, CT: Greenwood Press, 1992), 25, http://www.questia.com/read/27419298.

    Cited passage

    Thanks for trying Questia!

    Please continue trying out our research tools, but please note, full functionality is available only to our active members.

    Your work will be lost once you leave this Web page.

    Buy instant access to save your work.

    Already a member? Log in now.

    Author Advanced search

    Oops!

    An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.