data. Results for 480 data sets are presented in Table 7.10. The columns of the table indicate the number of clusters selected by a scree test, and the rows represent the correct number of clusters in the data. Thus, the diagonal of the table corresponds to the correct specification of the number of clusters identified by the scree test. A scree test is a graphical method used for visually identifying the change in level of a statistical measure. In this application the replication values are plotted across the number of groups in the clustering solution. A notable change in level of the statistic may indicate that the correct number of clusters has been found. The replication scree test was able to specify the correct number of clusters in 58% of the cases. When including those cases that were accurate to within ±1 cluster, 82% of the data sets were resolved correctly. Thus, further development of the replication methodology seems warranted.

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