What does a scree plot illustrate in factor analysis?

What does a scree plot illustrate in factor analysis?

• A. A graph of each factor (X-axis) against its eigenvalue (Y-axis) used to assess factor importance.
• B. A plot of p-values versus variables.
• C. A plot of residuals against fitted values.
• D. A bar chart of mean scores by group.

Answer: (A)

In factor analysis, a scree plot shows the eigenvalue for each potential factor plotted against its order (factor number). The eigenvalue tells you how much variance that factor explains. The plot helps you decide how many factors to keep by looking for an elbow where the line levels off; factors before the elbow explain substantial variance, while those after contribute little and may be treated as noise. This visual guide is used alongside rules like keeping eigenvalues greater than 1, but the key idea is comparing how much each factor adds to explained variance. It isn’t about p-values, residuals, or group means, which is why the other plots don’t fit.

In factor analysis, a scree plot shows the eigenvalue for each potential factor plotted against its order (factor number). The eigenvalue tells you how much variance that factor explains. The plot helps you decide how many factors to keep by looking for an elbow where the line levels off; factors before the elbow explain substantial variance, while those after contribute little and may be treated as noise. This visual guide is used alongside rules like keeping eigenvalues greater than 1, but the key idea is comparing how much each factor adds to explained variance. It isn’t about p-values, residuals, or group means, which is why the other plots don’t fit.