DECISION MAKING IN RESEARCH AND CLINICAL PRACTICE: Part 1: The basis for decision

This is the first part of a two-part paper. Part 1 describes the basis for decision making in research. The basic statistical procedures that provide the foundations for more advanced statistical techniques, the rationale underlying hypothesis testing, the nature of probability and its relevance to the normal curve, and the meaning of tests of significance and level of significance are discussed. These concepts provide the foundation for an understanding of the interpretation of decision rules and tests of significance, topics that will be discussed in Part II of the paper, to be published in a subsequent issue of this journal. All concepts and procedures are discussed in terms of their clinical relevance to the practising physical therapist.