# Assessing Interactive Web-Based Systems Using Behavioral Measurement Techniques
## 4 Data Analysis
### Usability Testing Analysis
#### 4.2.1 Usability Testing Analysis for Extra Website  
\(\bullet\) Task Success Metrics  
The percentage of success and failure of all four tasks is shown in Figure 2. Three users were able to complete Tasks 1, 2, 3, and 4 without any help, while one user needed help with Task 2, and one user failed to complete Task 3. Most of the users struggled to finish Task 2 because they were unable to find the \"Compare\" button. They completed the task by manually comparing the product price. Participant (P1) was unable to complete Task 3; she added the wrong item to the cart.  
\(\bullet\) Task Time Metrics  
The average task time of each task was calculated as shown in Figure 3. The users demonstrated a short time on Task 4 compared to the others. Tasks 1, 2, and 3 took a long time. Task 2 took the longest time, and its average time was 175.4 s because users were searching for similar products to add to a comparison list, but they could not find the \"Compare\" button. They again needed to go back and search for similar products that they wanted to compare, and then they had to compare products manually.  
\begin{table}
\begin{tabular}{l c c c c c c} \hline \hline \multirow{2}{*}{**Heuristic Evaluation Principle**} & \multicolumn{4}{c}{**Severity**} & \multirow{2}{*}{**Frequency**} & \multirow{2}{*}{**Average Severity**} \\ \cline{2-2} \cline{4-6}  & **1** & **2** & **3** & **4** & \\ \hline Visibility of system status & 1 & 2 & 1 & 1 & 5 & 2: Minor problem \\ \hline Match between the system and real world & 1 & 0 & 0 & 1 & 2 & 3: Major problem \\ \hline User control and freedom & 0 & 2 & 2 & 0 & 4 & 3: Major problem \\ \hline Consistency and standards & 1 & 1 & 2 & 0 & 4 & 2: Minor problem \\ \hline Error prevention & 0 & 1 & 0 & 0 & 1 & 2: Minor problem \\ \hline Recognition rather than recall & 0 & 0 & 1 & 0 & 1 & 3: Major problem \\ \hline Flexibility and efficiency of use & 0 & 1 & 1 & 0 & 2 & 3: Major problem \\ \hline Aesthetic and minimal design & 2 & 2 & 0 & 1 & 5 & 2: Minor problem \\ \hline Help users recognize, diagnose, and & & & & & & \\ recover from errors. & 0 & 0 & 0 & 1 & 1 & 4: Catastrophic problem \\ \hline Help and documentation & 0 & 0 & 0 & 1 & 1 & 4: Catastrophic problem \\ \hline \multirow{2}{*}{Total} & Frequency & 5 & 9 & 7 & 5 & 26 & \\ \cline{2-2} \cline{4-6}  & \% & 19.23 & 34.62 & 26.92 & 19.23 & \\ \hline \hline \end{tabular}
\end{table}
Table 4: Heuristic evaluation for Jarir website.  
* Error Number Metrics  
After observing the users and analyzing their performance while implementing the four tasks, as shown in Figure 4, the errors were most frequent in Task 2 followed by Task 3 and Task 1. Most participants committed errors with Task 2. They selected the wrong product for comparison because the search option showed irrelevant products. Some participants selected different product colors first and then found the correct product color in Task 1 and Task 3.  
Figure 4: Error number rate of Extra website.  
Figure 3: Task times of Extra website.  
Figure 2: Task success of Extra website.  
Considering all users and tasks, the overall success rate for the Extra website was 92.5, which (according to [72]) was above the average completion rate of 78%. The minimum average completion score across all tasks was 80%, which was also above the average completion rate of 78%. The total number of errors was 11, corresponding to 0.55 per task, which was less than 0.7, the average number of errors per task.
* Discovered Usability Issues  
Table 5 shows the identified usability issues and severity ratings for the Extra website. The usability issues pointed out problems related to effectiveness and efficiency.