# Cognitively Driven Arabic Text Readability Assessment Using Eye-Tracking
## 4 Materials and Methods
### Experimental Procedure  
All the experiments were conducted under experimental lab conditions. Because we conducted this research to understand the relationship between eye movements and text readability, the procedure involved collecting participants' eye movements. At the same time, they read six Arabic texts, one by one (so each participant was involved in six trials). We asked participants to read aloud to help us guarantee that they actually read the text and to enable us to hear how fast and how well they were reading. Each participant read all of the easy- and difficult-to-read texts. In order to minimize any possible influence of text order on reading [8; 67], we randomized the order of the displayed texts in each session.  
At the beginning of the experiment procedure, we provided a brief description of the texts to the participants. The session started by getting some information about each participant and his/her Arabic reading frequency, type, and amount per month. After that, the participant sat in front of the monitor and rested his/her head on the head support.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**File Name**} & **OSMAN** & **Sentences** & **Words** & **Syllables** & **Faseeh** \\  & **Readability Score** & **Count** & **Count** & **Count** & **Words Count** \\ \hline \hline \multicolumn{6}{c}{Andalusian Era Poems} \\ Text 1 & 157.15 & 8 & 38 & 48 & 0 \\ Text 2 & 144.58 & 8 & 33 & 54 & 0 \\ Text 3 & 163.60 & 8 & 39 & 36 & 1 \\ \multicolumn{6}{c}{Pre-Islamic Era Poems} \\ Text 4 & 101.99 & 8 & 37 & 120 & 1 \\ Text 5 & 123.92 & 8 & 39 & 102 & 2 \\ Text 6 & 114.10 & 8 & 40 & 113 & 1 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Summary of the main features of the texts using OSMAN.  
To ensure that we obtained accurate measurements, we conducted a calibration; crosses appeared on the screen and a participant's eye had to follow them.  
After successfully passing the nine-point calibration and validation that aimed to capture the actual gaze position on the display screen (a good calibration status for starting the experiment is to obtain a symmetric three-by-three grid and a good validation has an average error less than 0.5 and maximum error \(<\) 1), the instructions screen appeared. Subsequently, the participants read six texts in the following sequence: drift correction, reading 1 st text (Trial 1), drift correction, reading 2 nd text (Trial 2), and so on, until drift correction, reading 6 th text (Trial 6). After finishing the reading on a screen, they pressed any keyboard button to move on. Since the reading time for each text was open and not restricted to a specific time, a participant had to go to the next page immediately after finishing reading and before giving his/her feedback so that the device did not collect irrelevant data. Performing drift correction after each reading was important to avoid drift in the gaze position [78]. Thus, any problem in the gaze position would be detected.  
In addition to the previous reading task, we requested participants to verbally give their subjective readability about each text reading on a scale of four readability levels: Easy (E), Medium near to Easy (M/E), Medium near to Difficult (M/D), and Difficult (D). Each session lasted for approximately one hour, including calibration and the subsequent subjective readability questions.