Complexities of fonts in disfluent experiments

This study focuses on how fonts selected from different families have been used to test for disfluency. The motivation and standard for choosing a particular font for an experiment are not yet clearly defined from past studies. Drawing on methods in a systematic review of 10 articles published between 2007 and 2020, this article shows that authors prefer to use sans serif fonts in fluent conditions and serifs, scripts or handwritten fonts in disfluent conditions. In this study, disfluency manipulations were limited to reducing font sizes and percentages of grey or black. The largest size used was 56pt (fluent) and 18pt (disfluent) while the smallest was 12pt (fluent) and 10pt (disfluent). We observed that the opacity values of disfluent fonts ranged between 10% and 60%, making it unclear how disfluent a font can be. Apart from font sizes, fixation time, familiarity with materials and other controls influenced the results. This article reveals that a major gap still exists in research because of a lack of standard methods for determining the fonts used for testing subjects.