Online Book - Overview of Elementary Concepts in Statistics.

http://www.statsoft.com/textbook/

Chapters

What are variables? Correlational vs. experimental research Dependent vs. independent variables Measurement scales Relations between variables Why relations between variables are important Two basic features of every relation between variables What is "statistical significance" (p-value) How to determine that a result is "really" significant Statistical significance and the number of analyses performed Strength vs. reliability of a relation between variables Why stronger relations between variables are more significant

Why significance of a relation between variables depends on the size of the sample Example: "Baby boys to baby girls ratio" Why small relations can be proven significant only in large samples Can "no relation" be a significant result? How to measure the magnitude (strength) of relations between variables Common "general format" of most statistical tests How the "level of statistical significance" is calculated Why the "Normal distribution" is important Illustration of how the normal distribution is used in statistical reasoning (induction) Are all test statistics normally distributed? How do we know the consequences of violating the normality assumption?