Concept Portals include two types of significance testing; significance testing against the mean and against other concepts.
Statistical significance: mean
Shading indicates that a cell is statistically significantly different from the mean, at the Primary or Secondary confidence level indicated in the key below the portal.
Statistical significance: concepts
Capital and lowercase letters within a cell indicate a statistically significant difference from the concept that corresponds to the letter in the cell. A blank cell indicates that the concept in that column was not tested on the attribute in that row.