# Variable Validity, Reliability, Bias

• ### What are outliers in the data?

This excerpt from Engineering Statistics Handbook gives a definition for and examples of outliers. A sub-page also discusses Grubbs' Test for Outliers
• ### Religious Fundamentalism and Optimism

This example is designed to test whether religiosity is correlated with optimism. The page describes the study, has a link to the data set, and describes the method of analysis. Analysis includes ANOVA and regression.
• ### One-way Anova of PTSD Data

This page was written as instructions for a SAS lab assignment, but the example can be used with other programs. The study compares three treatments for rape victims against each other and a control group to see which treatment is most effective at reducing Post Traumatic Stress Disorder symptoms.

• ### Statistical Physics II

This course is second in the series of undergraduate Statistical Physics courses and features comprehensive lecture notes and assignments. Course topics include probability distributions for classical and quantum systems; microcanonical, canonical, and grand canonical partition-functions and associated thermodynamic potentials; conditions of thermodynamic equilibrium for homogeneous and heterogeneous systems; non-interacting Bose and Fermi gases; mean field theories for real gases, binary mixtures, magnetic systems, polymer solutions; phase and reaction equilibria, critical phenomena; fluctuations, correlation functions and susceptibilities, and Kubo formulae; evolution of distribution functions: Boltzmann and Smoluchowski equations.
• ### Data Collection: Data Cleaning Assignment

This activity guides students through the process of checking the validity of data, performing summary analysis, constructing box plots, and determining whether significant differences exist. The data comes from a study of mineral levels in older adults and is available in Minitab, Excel, SAS, and text formats.
• ### ** Introduction to Minitab

This laboratory introduces students to the basics of the Minitab software. Students make use of a basic example (water consumption and temperature) to introduce students to manipulation of data, calculation of descriptive statistics, creation of histograms, boxplots and scatterplots. Students are asked to hand in the results they have produced. Accompanying documents give model solutions.
• ### Construct Validity in Psychological Tests

A paper discussing the development of construct validity as applied to psychological studies.
• ### Overview: Reliability and Validity

This site discusses the issues of reliability and vailidity as related to research.
• ### Internal Validity Tutorial

This tutorial introduces 9 sources of threat to internal vailidity and asks the user to classify hypothetical experiments as either internally valid or invalid and identify the source of threat if invalid.