RESEARCH ARTICLE
Analysis of the Ruff 2 & 7 Test of Attention with the Rasch Poisson Counts Model
Mahsa Nadri, Purya Baghaei*, Zahra Zohoorian
Article Information
Identifiers and Pagination:
Year: 2019Volume: 12
First Page: 7
Last Page: 11
Publisher ID: TOPSYJ-12-7
DOI: 10.2174/1874350101912010007
Article History:
Received Date: 29/09/2018Revision Received Date: 16/12/2018
Acceptance Date: 7/1/2019
Electronic publication date: 31/1/2019
Collection year: 2019
open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: https://creativecommons.org/licenses/by/4.0/legalcode. This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Abstract
Background:
Attention is a basic neurocognitive function which is a prerequisite for performance on more complex cognitive tasks. The Ruff 2 & 7 test is a well-known measure of attention with a well-supported theoretical and empirical underpinnings.
Objective:
The Ruff 2 & 7 test, has not been subjected to rigorous item response theory analysis yet. The purpose of this research was to examine the fit of the Ruff 2 & 7 test to the Rasch Poisson Counts Model (RPCM).
Methods:
Responses of 138 nonclinical subjects to the Ruff 2 & 7 test were analyzed with the RPCM measurement model using ‘lme4’ package in R. The fit of the individual items (blocks) and the overall test to the model were examined.
Results:
Findings showed that three out of seven scoring techniques fit the Rasch model. The scoring techniques which fitted the model were total number of characters cancelled, total number of characters correctly cancelled, and total number of characters correctly cancelled minus errors of commission.
Conclusion:
Three of the scoring techniques fit the RPCM which support the internal validity of the test when these scoring procedures were employed. Therefore, the Ruff 2 & 7 test is psychometrically uni-dimensional when these three scores are computed.