The Linearity Study performs a regression analysis using the standard variable as the X variable and the bias as the Y variable. This analysis examines the relationship between bias and the size of the part. Ideally, you want to find a slope of zero. If the slope is significantly different from zero, you can conclude that there is a significant relationship between the size of the part or variable measured as a standard and the ability to measure.
The Linearity Study option is available only when a Standard variable is provided in the launch window.
The report shows the following information:
• Bias summary statistics for each standard.
• An ANOVA table that tests if the slope of the line is equal to zero.
• The line parameters, including tests for the slope (linearity) and intercept (bias). The test for the intercept is useful only if the test on the slope fails to reject the hypothesis of slope = 0.
• The equation of the line appears directly beneath the graph.
The Linearity Study red triangle menu contains the following options:
Set Alpha Level
Changes the alpha level that is used in the bias confidence intervals.
Linearity by Groups
Produces separate linearity plots for each level of the X, Grouping variables that you specified in the launch window.