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Contingency tables and association statistics. (from Chapter 9). 1. Association between qualitative variables. Association is a generic term referring to the relationship of two variables Correlation measures strictly refer to quantitative variables
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Contingency tables and association statistics (from Chapter 9) 1
Association between qualitative variables Association is a generic term referring to the relationship of two variables Correlation measures strictly refer to quantitative variables Association, generally refers to qualitative variables Two qualitative variables are said to be associated when changes in one variable lead to changes in the other variable (i.e. they are not independent).For example, education is generally associated with job position. Association measures for categorical variables are based on tables of frequencies, also termed contingency tables 2
Expected frequencies under independence Example: preferences on differentkinds of chicken expected frequency: fij* Es: 2.9=(24*12)/100 empirical frequencies fij (%) categorical variables independent 4
In EXCELL: PIVOT TABLES Examplefrom file: DEMOSTUD.XLS Frequences: Education/marital status and Education/job satisfaction 5