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ERIC Number: ED120208
Record Type: Non-Journal
Publication Date: 1976-Apr
Pages: 13
Abstractor: N/A
Reference Count: N/A
An Analytical Investigation of the Robustness and Power of ANCOVA with the Presence of Heterogeneous Regression Slopes.
Hollingsworth, Holly H.
This study shows that the test statistic for Analysis of Covariance (ANCOVA) has a noncentral F-districution with noncentrality parameter equal to zero if and only if the regression planes are homogeneous and/or the vector of overall covariate means is the null vector. The effect of heterogeneous regression slope parameters is to either increase or decrease the power of the F-test of ANCOVA. This depends on the relationship of the true difference of the treatment effects of two groups with respect to the dot product of the vector of overall covariate means and the vector of the difference of the two groups' slope parameters. (Author/RC)
Publication Type: Reports - Research
Education Level: N/A
Audience: N/A
Language: N/A
Sponsor: N/A
Authoring Institution: N/A