Analysis of Variance &Objectives of Analysis of Variance

Analysis of Variance

Analysis of variance is the procedure used when we want to investigate situations where there are more than two levels of the independent variable. Stated another way, when there are more than two groups, and we would like to compare their performance across a dependent variable use ANOVA. Using ANOVA, we determine if the groups differ on some continuous variable of interest. An example of a situation where ANOVA would be used is a teacher who wants to find out if three different reading texts (Holt, Ginn, Lippincott) produces different reading levels in children. Another example requiring the ANOVA technique would be, "Are the survival rates different for five different groups of AIDS patients when the five groups are defined by different dosage levels of a new experimental drug?"

Objectives of Analysis of Variance

@      It identifies the causes of variation and sort out corresponding components of variation with associated degrees of freedom.

@      It provides far test of significance based on  distribution.