ABSTRACT
This chapter covers some basic principles of item writing for both ability tests and personality tests. It introduces classical item analysis as a quick and straightforward way of identifying and eliminating items which perform badly. The chapter stresses that any scale is simply a sample of items from the domain which the scale seeks to measure. Constructing ability scales, rather than knowledge-based scales, is more difficult because it is less obvious how one should sample the whole domain of possible items. Short, common words, short sentences and simple grammar are advisable unless the population for whom the scale is designed is well educated and will answer the items in their first language. Internet administration of personality scales is straightforward; internet-based administration of ability scales is less easy, particularly if graphics are required or if time limits are needed. The chapter describes how a typical group-testing session might be run.
