Figure 12.

Interrater reliability of Bar-Tip Limit (BTL) index coding demonstrates high repeatability of coding method. Coauthors SHK and JBW independently computed the BTL index for a subset of 201 drawn graphs (of 551 total). Each dot represents both BTL indices for a given drawn graph (y-value from SHK, x-value from JBW). Semitransparent dots code overlap as darkness. The black line is a line of equivalence, which shows x = y for reference. The line of best fit is blue. The close correspondence of these two lines, and the close clustering of dots around them, demonstrate high repeatability of the BTL index coding procedure.