MIT Statistics for Applications Course
Other MIT OpenCourseWare courses include Introduction to Probability and Statistics and Mathematical Statistics.
Carnegie Mellon University Statistical Reasoning Course
Probability and Statistics course is also available on the website of CMU Open Learning Initiative.
Decision Tree
The link is based on the book "A Guide for Selecting Statistical Techniques for Analyzing Social Science Data" (Second Edition).
Decision Table
The link is associated with the book "Intuitive Biostatistics: Choosing a statistical test" (First Edition).
P-value Calculator
For a sample from a population with a known proabability distribution, a p-value can be calculated using an online calculator. The program was developed by Dr. Hossein Arsham of the University of Baltimore.
Note: Power and sample size calculation is intended to help design a study. It is not intended to be conducted after the data have already been collected. We highly recommend that a researcher who is planning for a study consults a professional biostatistician well before the initiation of the study.