Missouri State University
Missouri State U.: Introductory Statistics: T Test: One and Two Tailed T Tests
One-tail and two-tail t-distribution tests are explained here in detail. When is one the preferred method? A good comparison is offered.
University of Glasgow
Steps Glossary: Chi Squared Test for Homogeneity
A quick definition and explanation of the Chi-Squared Test for Homogeneity.
Rice University
Hyper Stat Online Statistics Textbook: Chi Square Test of Independence
The introduction to the Chi Square Test of Independence. An example is provided with an explanation.
Other
Westgard Qc: Hypothesis Testing
A good description of hypothesis testing. Refers to the null hypothesis as a "straw man" that is either left standing or knocked down. Other links are provided to related parts of the topic.
Other
Westgard Qc: A Note About the "Paired T Test" in Method Comparison
A note about paired t-tests within a larger article dealing with hypothesis testing.
Other
University of the Sciences: Chi Squared Test
Explains what the statistical Chi-Squared Test is and how it is used in biology. A good cross-curricular site.