Dev Psc Measure

DEVELOPMENT OF A PSYCHOLOGICAL MEASURE

INTRODUCTION The process of developing a reliable and valid psychological measure is a complex task. In this paper, the author hopes to further explain how to construct a test which can be considered both valid and reliable.

Steps to developing a psychological measure The steps to follow when developing a psychological measure can seem daunting and complex. There are nine basic steps which need to be followed:

1.THE PLANNING PHASE This is where the aim of the measure needs to be decided on and stated. The characteristic or construct to be measured, what the measure will be used for, and the target group (population) for the measure will also need to be defined. Once this has been clarified, one can decide how the test scores will affect decisions (or what decisions can be made based on test scores). An important stage in planning is whether the performance is compared to a criterion or a group norm.

In order to define the content of a measure, one needs to have a defined purpose of a measure. The construct needs to be operationally defined, by undertaking a literature review (research process) of the main theoretical viewpoints of the construct. The purpose of the measure is clearly vital, as it serves the basis for constructing the measure. In this phase, 'keying' is used ? where information is gathered about the 'aspects of the construct on which these groups usually differ'. (An Introduction to Psychological Assessment. Foxcroft and Roodt. P72). e.g. Items are needed to discriminate between individuals, so as to allow the assessor to view the various 'risk' groups.

The format and number of each type of item is the next step in the planning phase. The format of the test will vary according to the construct being measured. There are open-ended items (no limits placed on the test-taker), forced-choice items (like multiple-choice, where careful decisions are involved), sentence completion items, essay items (which test for...