“…Jordan et al (1991) initially identified guessability as an important usability design component to measure the cost (time spent on tasks or mistakes made) paid by product users when performing a task for the first time, the higher the guessability, the lower the cost (Chan & Chan, 2013; Chan & Ng, 2010a; 2010b; 2012; Ng & Chan, 2007). Since users need to recognize symbols in a short time and try to avoid making mistakes, many previous studies (Chan & Chan, 2013; Chan & Ng, 2010a; 2010b; 2012; Liu et al, 2019; Ng & Chan, 2007; Siswandari et al, 2015) used guessability as a reasonable index for comprehensibility of a symbol, to investigate the comprehension performance of users with regard to symbols (Liu et al, 2019). So guessability score refers to the accuracy of guessing the meaning of a symbol, which is used to measure whether a symbol could or could not convey the intended meaning (Chan & Chan, 2013; Chan & Ng, 2010b; 2012; Siswandari et al, 2015).…”