ERIC Number: ED204360
Record Type: Non-Journal
Publication Date: 1981-Apr
Reference Count: N/A
Models of Continuous Growth and Their Implications for the Analysis of Nonequivalent Control Group Designs.
Blumberg, Carol Joyce; Porter, Andrew C.
Analysis strategies are discussed for the nonequivalent control group design when three models of continuous natural growth are known. For Model I type natural growth it was shown that the fan spread hypothesis always holds, and Analysis of Covariance (ANCOVA), Analysis of Variance (ANOVA) of Residualized Gain Scores, and ANOVA of Standardized Change Scores all are potentially correct analysis strategies. For Model II and Model III type natural growth it was shown that the fan spread hypothesis holds and the ANCOVA, ANOVA of Residualized Gain Scores, and ANOVA of Standardized Change Scores are potentially correct analysis strategies only when Model II and Model III type natural growth reduce to Model I type natural growth. Further, it was shown that given any natural growth situation, there is a value of K for which ANOVA of Index of Response is a potentially correct analysis strategy. In order that an index of response works, the exact form of natural growth must be known. Most growth models, and in particular most linear growth models, do not conform to the fan spread hypothesis nor are the usual analysis strategies correct for these models. (Author/RL)
Publication Type: Speeches/Meeting Papers; Reports - Research
Education Level: N/A
Authoring Institution: N/A