Legibility Investigations: Controlling Typeface Variables

One frequent problem in legibility investigations is that the tested
typefaces vary on too many variables. In an investigation which
compares typefaces that – at the same time – vary on letter width,
weight, contrast and skeleton, it will be difficult to determine
precisely why the findings come out as they do, and the external
validity suffers. By applying a method of integrating design practice
with academic research, I have designed a new typeface family
that addresses this problem of multiple typographical variables. At
its current stage, the typeface family Neutral Test has seven
members. One is the master typeface; three of the remaining
typefaces have one stylistic feature that differs from the master
(skeleton, weight, and width); and three have two stylistic features
that differ from the master (weight/skeleton, weight/contrast and
weight/width). In an experimental investigation where the test
material is based on the different members of Neutral Test, the
researcher will thus be able to identify the specific stylistic feature
that causes a given difference in performance.