Search Results for: contingency table

Abdi, H. (2009) The Greenhouse-Geisser correction. In Neil Salkind (Ed.), Encyclopedia of Research Design. Sage. Thousand Oaks, CA. http://www.utdallas.edu/~herve/abdi-GreenhouseGeisser2010-pretty.pdf Abdi, H. (2010) Coefficient of variation. Encyclopedia of Research Design. Sage. Thousand Oaks, CA https://www.utdallas.edu/~herve/abdi-cv2010-pretty.pdf Abdi, H. & Molin, P. (2007) Lilliefors/Van Soest’s test of normality. Encyclopedia of measurement and statistics. Neil Salkind (Ed.). Sage, Thousand … Read More

Although all the statistical analyses described on this website can be done with standard Excel capabilities, it is often easier to use the supplemental functions and data analysis tools provided in the Real Statistics Resource Pack. The functions provided in the Real Statistics Resource Pack are summarized in Real Statistics Functions. Here we briefly review … Read More

Basic Concepts In the non-comprehensive models at least one of the variables is not used. We show how to calculate the expected frequencies for one such model, namely (A, B). The degrees of freedom are abc – (a – 1) – (b – 1) –1 = abc – a – b +  1. Example Figure … Read More

Basic Concepts The homogeneous association model for (AB, BC, AC) consists of the saturated model with the λABC term dropped. It therefore has (a – 1)(b – 1)(c – 1) degrees of freedom. For Example 1 of Three-way Contingency Tables this is (2 – 1)(2 – 1)(3 – 1) = 2 degrees of freedom. For … Read More

Basic Concepts The model for (A, B, C) is ln y = λ + λA + λB + λC and has abc – [(a – 1) + (b – 1) + (c – 1) + 1] = abc – (a+b+c) + 2 degrees of freedom. For Example 1 of Three-way Contingency Tables the mutual independence … Read More

Basic Concepts There are three partial independence models (A, BC), (B, AC) and (C, AB). We’ll look at the first of these; the others are similar. The model for (A, BC) consists of the saturated model with the λAB, λAC and λABC terms dropped. It therefore has (a – 1)(b – 1) + (a – 1)(c – … Read More

Basic Concepts There are three conditional independence models (AB, BC), (AC, BC) and (AB, AC). We’ll look at the first of these; the others are similar. The model for (AB, BC) consists of the saturated model with the λAC and λABC terms dropped. It therefore has (a – 1)(c – 1) + (a – 1)(b … Read More

Background In Linear Regression Models for Comparing Means and ANOVA using Regression we studied regression where some of the independent variables were categorical. In this part of the website, we look at log-linear regression, in which all the variables are categorical. Log-linear regression provides a new way of modeling chi-squared goodness of fit and independence problems (see Independence Testing and Dichotomous Variables … Read More

In Independence Testing we use the chi-square test to determine whether two variables are independent. We now look at the same problem using the correlation coefficient with dichotomous dummy variables. Example Example 1: Calculate the point-biserial correlation coefficient for the data in Example 2 of Independence Testing (repeated in Figure 1) using dichotomous variables. Figure … Read More