Good legibility (e.g. different forms of letters that are clearly discernable) and readability (e.g. perfect spacing of the letters) are of prime importance for an educational typeface, in order to avoid unnecessary difficulties for beginning readers.
The following figures show legibility and readability problems in the Austrian “Schuldruckschrift” (educational typeface in block letters) which may serve as examples for faults in educational typefaces of other countries:
1. Simply mirrored or rotated letters
Two “identical” cups:
Four “different” letters:
Most children recognise a cup as a cup, regardless if it is put upside down or turned around.
The Austrian “Schuldruckschrift” has four letters that can be simply mirrored or rotated: d, b, q and p. Many children have great difficulties in differentiating these letters – they see a circle with an attached line, independent from its orientation. What works well with the cup can make learning to read a real challenge.
In the font “Times New Roman” these characters look like this:
They are easily discernible, even when they are upside down.
2. Insufficient ratio between ascender and x-height
The so called x-height is the term for the height measured from the baseline to the top of a small letter that has no ascender. The ascender is the part of the small letter reaching above the x-height – e.g. in an h or k. Characters like h and n or d and a can be easily mixed up, if the ascender in relation to the x-height is too short:
In the case of the Austrian “Schuldruckschrift” the ascender of the h compared to the x-height of the n is too short. The length of the ascender in “Times New Roman”, however, is sufficiently long and these letters cannot be mistaken for each other.
3. Letter combinations that are easily misread
There are letter combinations that give rise to confusion with other letter combinations. In the Austrian “Schuldruckschrift” an r followed by an n can easily be misread as an m:
This is never the case with “Times New Roman”.
4. Ambiguous characters
In creating an educational typeface it is important to take care that a capitalized I can be clearly differentiated from the small letter l or the figure 1: