Understanding Cronbach’s Alpha in SPSS
In this section, we are going to learn about Cronbach’s alpha. Cronbach’s alpha is a coefficient that gives us the measure of internal consistency of a test. By internal consistency, we mean to what extent the indicators of the test are related to each other and to what extent they are conversing on the main global construct that they are trying to address.
- For example, suppose a scale of happiness consists of 10 items. If these 10 items are fairly correlated to each other, and they are all measuring happiness in a true way, it will have a good Cronbach alpha
- It is the most popular measure of scale reliability in Psychology and education, as reported by Daniel and Witta in 1997. The beauty of Cronbach’s alpha is that it can be used when we are having a liquor type continuous scale, or we are having a dichotomize scale in which responses have been measured into yes and no or right or wrong and in such other way. The Liquor type scale is a nominal But considering all the properties of an ordinal or continuous scale or dichotomize scale, Cronbach alpha is sufficient for them. So it does not matter whether we are using a nominal, ordinal or continuous scale. In all the cases, we can report the Cronbach’s alpha. The Cronbach’s alpha is named after the American psychologist Lee Cronbach.