Analysis of Variance (ANOVA): Mathematical Breakdown

1. Analysis of Variance (ANOVA) (Ronald Fisher)

ANOVA compares means across multiple groups to determine if observed differences are statistically significant.

Formula:

F = (SSB / (k - 1)) / (SSW / (N - k))

Where:
F: F-statistic
SSB: Sum of squares between groups (variance explained by group differences)
SSW: Sum of squares within groups (variance within each group)
k: Number of groups
N: Total number of observations

2. Categorization and Subjective Weights

This example illustrates how subjective weighting of variables can affect group comparisons using ANOVA.

Groups:

Subjective Weights:

Weighted Scores:

SSB Calculation:

Overall Mean = (88 + 68 + 42) / 3 = 66
SSB = Σ(GroupSize × (GroupMean - OverallMean)²)

SSB = (1 × (88 - 66)²) + (1 × (68 - 66)²) + (1 × (42 - 66)²)
= 484 + 4 + 576 = 1064

This example demonstrates how subjective weights can influence group rankings and justify resource allocation decisions.