Several findings can be highlighted.
- Craig (Craig 1980) suggested that aged people read horizontal letters better than vertical. Serif type calls for less leading than sans serif type because the serifs reinforce the horizontal eye flow (Rehe 1990). From research done generally it is accepted that Serif has higher impact on legibility because it is free of distractions (Garcia 1981).
- Watanabe from New England College of Optometry suggest that letter compression has a significant impact on reading (Watanabe 1994). A font of 4.5 written on black with white contrast was easier to read than the same message with a font size of 6 written with yellow on red contrast and black text on a white background is most preferred (Bix 2002).
- Colour contrast has a strong effect on the legibility index. Michigan State University has done an experiment to test legibility on 6 different colour contrasts. The colours chosen were ones that are used widely in pharmaceutical labels especially on warning statements and cautions (Bix 2002). Comments from focus groups from patients aged 51-80 were collected. The comments showed a definite dislike of both yellow on red and the black on red colour combinations (Lockhart 1995).
- Colour-blindness affects 1 in 12 men in Australia (8%) and 1 in 400 in Women (0.0025) (DPCD 2011, April). Total colour blindness where one perceives only black and white is extremely rare and it affects 1 in 33,000 in the world (DPCD 2011, April).
- Department of Planning and Community Development (DPCD 2011, April) came up with a ‘universal’ design to improve communication in the following three ways: using labels, annotations and applying different style labels inside a map as below can reduce ambiguity. Showing annotation can give clearer guidelines to the map. Applying style with different shapes, different types of filling and shades such as dots, squares, varying sizes of dotted lines can help to overcome visual discrepancies. (DPCD 2011, April), p. 19.
Figure 3: Legend showing labels: “Adding labels inside a bar graph can increase readability”
Figure 4: Using different graph styles can help highlight differences
- Powsner et al. (Powsner et al. 2000) found that there is a significant difference in clinicians’ understanding of the content of a pathological report based on the physical presentation of the information in the report. The participants compared existing formatted reports with a new streamlined report format with changes including spacing, highlighting, positioning of information, and font selection. They found that these items did not, in and of themselves, contribute to the content of the report; however, they did appear to contribute substantially to the comprehension of that report, despite nearly identical wording.
- Kandula and Zeng-Treitler (Kandula and Zeng-Treitler 2008) attempted to create a ‘gold standard’ for the readability measurement of health texts. From evaluation of 324 documents, noted that a document’s style - such as font, sub-headings, and bulleted lists affected the document’s readability.
- Poulton (Poulton 1972) tested several fronts for legibility and found that x height was a significant factor in legibility and that fonts with the same x height (rather than point size) had relatively the same level of legibility.
- Bernard et al. (Bernard et al. 2001) identified 5 font types that were perceived as being the most legible: Courier, Comic, Verdana, Georgia, and Times.
- Dark text on a light background provides the best legibility (Arnold 1972; Bradley et al. 1994; Sumner 1932). Bradley et al. (Bradley et al. 1994) also suggest that these combinations avoid difficulties associated with red/green colour blindness.
- The use of ALL CAPS is generally not recommended in the literature, being regarded as less legible (Wheildon C 1995) than sentence case (Wheildon C 1995).
- Bix (Bix 2002), in reviewing the many different aspects of legibility, concluded that the individual elements of design and layout do not determine legibility, but that sufficient legibility is the outcome of the sum of the parts e.g. font, font size, leading, colour etc.