Diamond Mean Comparison Charts

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.

• In groups with equal sample sizes, overlapping marks indicate that the two group means are not significantly different at the 95% confidence level.

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.

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

• Here, levels of two grouping variables split the response values from a single numeric column.
• You can choose which components of the split should represent the legend entries and which should represent the X-axis labels; in the example below, the legend entries represent levels of the 2^nd grouping variable, the X-axis labels represent levels of the 1^st grouping variable.
A Two-Way Diamond Mean Comparison Graph

Using a Worksheet Layout With One-Grouping Variable

• Here, levels of a grouping variable split the response values from multiple numeric columns.
• You can choose which components of the split should represent the legend entries and which should represent the X-axis labels; in the example below, the legend entries represent levels of the grouping variable, the X-axis labels represent the response variables.