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Diamond Mean Comparison Charts

What Does a Diamond Mean Comparison Plot Display?

In these plots, the horizontal dashed line is the overall mean. The line through the center of each diamond is the group mean. The top and bottom diamond vertices are the respective upper and lower 95% confidence limits (CI) about the group mean. The short horizontal lines flanking the means are overlap marks.

A Graphical Display of Elements of a Diamond Mean Comparison Chart

One-Way Diamond Mean Comparison Charts

The one-way graphs are designed for a worksheet layout in which scores from different samples/groups are stored in separate numeric columns. The X-axis tick intervals can be equally spaced, or displayed proportional to the sample size.

One-Way Diamond Graphs With X-Axis Tick Intervals Displayed
(a) Equally Spaced, and (b) Proportional to Sample Size

Two-Way Diamond Mean Comparison Charts

A two-way bar plot allows comparing mean, median, minimum or maximum values of response data (scores, measurements) obtained from pq levels of two experimental factors (i.e., k=pq samples/groups).

Using a Worksheet Layout With Two-Grouping Variables

Using a Worksheet Layout With One-Grouping Variable