ABSTRACT
In this chapter, the author discusses the concepts of basic statistics in education. They discuss two types of statistics: central tendency and variability. While most of our statistical tests will use variance (or the sum of squares) as a key component, it's difficult to interpret directly, so most often researchers will report standard deviation, which is more directly interpretable. Standard deviation isn't exactly a different statistic than variance—it's actually a way of converting variance to make it more easily interpretable and to standardize it. The authors explores ways to describe samples using central tendency and variability estimates. They also demonstrates how to evaluate whether a sample is normally distributed, and the properties of the normal distribution. Non-normal distributions might be non-normal due to skew, kurtosis, or both. It's fairly common, though, for skew and kurtosis to occur together. Finally, they demonstrates how to calculate most of these estimates using SPSS.
