One Half or 50%? An Eye-Tracking Study of Number Representation Readability

Abstract

Abstract. Are numbers expressed as digits easier to read and understand than written with letters? What about fractions and percentages? Exact or rounded values? We present an eye-tracking study that attempts to answer these questions for Spanish, using fixation and reading time to measure readability as well as comprehension questions to score understandability. We find that digits are faster to read but do not help comprehension. Fractions help understandability while percentages help readability. No significant results were found concerning the influence of rounding. Our experiments were performed by 72 persons, half of them with dyslexia. To the best of our knowledge, this is the first study that addresses the cognitive load of number representation in any language, even more for people with dyslexia.

Is visual content in textual search interfaces beneficial to dyslexic users?

“…Rello et al (2013a) used eye tracking to investigate cognitive load associated with different forms of number representation, and how different conditions affected understandability and readability for dyslexics. They found that numbers presented as digits were more readable than digits presented as words, and that percentages were faster to read than fractions.…”

Frequent Words Improve Readability and Short Words Improve Understandability for People with Dyslexia

“…fantabulous [11], words with errors [9], non-words, 9 e.g. happisfaction [9], and numerical expressions [40]. In the experimental design we did not use words of such characteristics to control other possible effects.…”

Keyword Highlighting Improves Comprehension for People with Dyslexia

“…In this way, a visitor can now contemplate paintings and sculptures that, for the first time, are exposed in the gallery. (h) one text has two numerical expressions (Rello et al, 2013b) and the other has two foreign words (Cuetos and Valle, 1988), both being elements of similar difficulty; and (i) have the same number of highlighted keyphrases.…”