# Assessing Interactive Web-Based Systems Using Behavioral Measurement Techniques
## 6 Discussion  
This research has integrated three behavioral measurement techniques: heuristic evaluation, usability testing, and eye-tracking to evaluate the website usability of Extra and Jarir. This section discusses the findings in three major aspects: first, it highlights some detected usability problems. Next, this section illustrates the major differences between the applied techniques in terms of the number of detected problems, their severity, and their nature. Finally, this section lists the strengths and weaknesses observed on each website. As indicated in [15], usability problems detected on e-commerce websites mostly relate to page navigation, search facilities, purchasing, consistency, design, security, and lack of certain functionalities. The findings for both websites agree with these categories, in particular, the search optimization and missing functionalities. In general, the heuristic evaluation yielded many interesting usability problems. Among the catastrophic problems was the lack of input validation for the phone number on the Jarir website and the subsequent absence of any error messages when the verification failed. This issue may degrade the UX, especially as it comes shortly after the buying decision is made. The users may unknowingly mistype their phone number and not receive any notification of their order for no apparent reason as they received no error message. One interesting usability problem is the restriction placed by both websites on the possible number of ordered items. For instance, on both websites, users can not order more than one expensive item, such as a smartphone or a TV. This is a critical weakness as it limits shopping behavior and may require users to order several times. In fact, such items are not commonly ordered in bulk. However, an alternative, better practice would be to display a warning message and emphasize the total cost of the order. Moreover, both the Jarir and Extra websites lack documentation and user guides. This seems to be a common usability problem among e-commerce websites, as indicated by [74]. Business owners and web developers may assume that users are already familiar with online shopping. Despite the recent rise in the number of online shoppers in Saudi Arabia and worldwide, many users are still inexperienced or unsure and may need to frequently access help pages. The Extra and Jarir websites also share another usability problem, and that is the inconvenience of the slider element that moves one item at a time. Thus, if the user wishes to slide 10 items to the left, they need to click the left arrow 10 times. This may annoy users and redirect them to another navigation option. Among the problems identified by usability testing but not detected by experts was the reappearing offers on both websites. Users were interrupted several times while performing tasks by the website's ads, which led to user distraction and confusion. The marketing efforts in such scenarios are not only lost, but contribute to the users' dissatisfaction. This problem was detected neither by experts nor via eye tracking. Experts may not be as annoyed with the disruption as ordinary users. On the other hand, on eye tracking, no significant fixation was recorded on the pop-up messages. The user attempted to locate  
Figure 22: Behavioral measurement techniques severity rating for Jarir website. the \"Exit\" button to close the message. Therefore, such problems are not detected by eye tracking. Furthermore, the menu design, the lack of smart search, and the low quality of search results all led to usability problems. Despite this fact, the Jarir website performed better than the Extra website in terms of search results. These problems will hinder the user's activity on the website and restrict their shopping experience. The eye-tracking technique revealed that the main menu categories on the Extra website would disappear with the slightest movement of the mouse pointer. This was reflected in longer and higher density fixations around the main menu.