Tiresias :: Scientific & technological reports

LPfont - An investigation in the legibility of large print typefaces by Sylvie Perera

7 Conclusion

This project revealed that the character form of Tiresias is significantly more legible than either Times New Roman or Arial so the null hypothesis can be rejected. People with poor reading vision seemed to appreciate Tiresias more than people with fair or good reading vision.

Further studies of specific typological factors provided indications of the preferred levels by people that were current or potential readers of large print books. The typeface with the darkest weight that was tested, was favoured by the subjects. This supports the fourth hypothesis which states that 'the bolder the typeface the more legible it is to visually impaired large print readers'. The preferred typeface is darker than currently used typefaces in large print books. Normal spacing, similar to that used in large print books was preferred and had a higher reading speed than the enlarged spacing tested. This finding is contrary to the third hypothesis that was based on the belief that the wider the spacing, the more legible the typeface would be for visually impaired readers. The semi-serif version of the typeface that resembles a bracketed serif (which is not as exaggerated as a slab serif) produced a higher reading speed than either a sans serif or seriffed version of the typeface. The degree of serif hypothesis was not supported. It appears that a slight degree of serif which accentuates the characters ends without distracting from the simple form actually increased legibility. There is not a linear correlation between the degree of serif and legibility. Punctuation marks that were rounded and slightly enlarged were preferred by subjects. This partially supports the fifth hypothesis, the punctuation marks were more legible when exaggerated but not at the point where they were too bold and distracted from the text.

From these scientific results a large print version of Tiresias was designed and developed (see appendix 7). To determine whether this typeface is significantly more legible than currently used typefaces, it will be tested in a large print magazine - 'Big Print'.

7.1 Guidelines

Proposed features below do not relate to the typeface but inform of the appropriate format for large print text. These can be utilised in conjunction with the typeface.

· Black ink on white / off white matt paper
· Opaque paper to minimise bleed through of ink
· Left justification (flush left / ragged right)
· 55 - 60 characters per line
· If using bold ensure white space within characters is not detrimentally diminished
· Minimise italics
· Minimise all caps
· Do not use underlining
· Do not use hyphenation

7.2 Limitations

Large print producers limitations were not specifically known before the typefaces were produced. For example the enlarged spacing tested may have been impractical for use in a large print book even though it may have been preferred by the readers. Some questions relating to where people read their large print books was not analysed or commented upon after collecting the data. Variables could not be given specific units because they are relative not absolute values e.g. the weight of the typeface does not have a unit value. It is not known whether different levels of the variables would be preferred by users. These could not be tested because distinct levels beyond the 'just noticeable difference' had to be used so subjects would be able to distinguish between typeface samples. For a factor such as the weight of the typeface, because the preferred version was of the heaviest weight it is unsubstantiated if subjects would have preferred an even bolder typeface. It is assumed a further increase in weight would compromise the legibility of the characters.

7.3 Further Work

Research into the optimum leading for a large print would give large print producers a scientific basis for their decisions. Application of this large print Tiresias typeface to conditions other than a large print book should be made with knowledge and understanding. People that read large print books tend to do so at word recognition distance. Some people that are unable to read continuous text because they read at character recognition distance would benefit from research into their specific reading situation and relevant typographical factors.

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