ABSTRACT
Having completed initial data analysis (IDA) you may now want to consider inferential statistical procedures. This stage of the analysis will be based on some kind of probability model and will more than likely involve one or more statistical tests. With a number of alternative statistical tests to choose from the new researcher is often unsure about which test to use. A few general considerations will be presented first, then a strategy for choosing among the possible statistical tests will be described and summarized in the form of a decision chart. Other considerations such as statistical power and its relationship to statistical tests, alpha (Type I error), sample size, effect size, and variance will be discussed, and the ubiquitous question about sample size will be addressed. Examples of sample size and power calculations are presented. Finally, testing for normality of distributions is illustrated and what to do when distributions are non-normal is considered.
