Use the interval plot to display the mean and confidence interval for each group.
The interval plots show the following:
- Each dot represents a sample mean.
- Each interval is a 95% individual confidence interval for the mean of a group. You can be 95% confident that the group mean is within the group's confidence interval.
Interpret these intervals carefully because your rate of type I error increases when you make multiple comparisons. That is, the more comparisons you make, the higher the probability that at least one comparison will incorrectly conclude that one of the observed differences is significantly different.
In these results, Blend 2 has the lowest mean and Blend 4 has the highest. You cannot determine from this graph whether any differences are statistically significant. To determine statistical significance, assess the confidence intervals for the differences of means.