Introduction

This part introduction presents an overview of the key concepts discussed in the subsequent chapters. The part explains that the re-define validity in effect as the interpretability of observations/measurements in terms of the theory in which reader play a part. It describes the basic procedures for coding survey data, including the different types of coding frame which can be employed. The part classifies observations/responses in terms of simple and meaningful categories. It explains the principle of construct validity via the investigation of the dimensionality of attitude items culled from exploratory interviews. The part presents Lee J. Cronbach's Alpha reliability coefficient as a criterion for the reliability of the composite measures obtained from sets of these items. Validation of these measurescomes from an investigation of their relationships with other variables predicted from the theory in which they play a part.