The purpose of this dissertation is to provide a comprehensive analysis of the current Loughborough University web site (http://www.lboro.ac.uk). Through the course of this report, utilization of Eye tracking methodology has been used to determine whether the website successfully accomplish the business goals and objectives of Loughborough University.
The following are the objectives of this dissertation:
To conduct the usability study on current website system of Loughborough University by using Tobii eye tracking technology.
To present and propose some new recommendations that would help the developers to upgrade in the current website.
An organization's Web site is a gateway to its information, products and services. As such, it should ideally be a reflection of the needs of the clients it serves. Unfortunately, Web site design and development is often driven by technology or by organizational structure or business objectives, rather than by user needs. In recent years however, Web site owners and developers have gradually begun to acknowledge and address the issue of usability. Good usability is a key quality of any college or University website. It is needed to clearly articulate the business goals of a visited site and it enables users to accomplish their tasks more effectively by choosing the right actions and navigating to the right pages. Various College and Institutional websites have failed during the last couple of years, because of missing user retention and navigational problems. Poor usability of their websites is one of the major causes of their failure. In a generic layered model of university websites, the marketing layer (presentation layer) and the usability layers seem to be separated from each other, at first glance. The usability layer lies beneath the marketing layer. The presentation layer defines issues like structure, layout, design and target customers. However, some marketing aspects, e.g. the definition of target groups and business goals may directly interfere with usability issues and therefore have to be taken into account when an overall usability assessment of a website is done.
CHAPTER 2: LITERATURE REVIEW
USABILITY
Everybody knows very well that an information system should provide the essential functions to the users to accomplish their tasks. But functionality alone is not sufficient. The other determinants of system acceptance are functionality and Usability. Basically, functionality refers to the degree in which a system provides functions to their users to complete their tasks and usability is concerned with the ease of use, a user related and task related concept. Full functionality cannot be achieved until the system is not usable. Therefore Usability must be elevated to the similar precedence as functionality. Mainly Usability refers to the extent to which the user and the system can communicate clearly without any misunderstanding through interface. Goodwin defines the usability as the degree of compatibility of the system with the user's cognitive characteristics for communicating and understanding and problem solving. On the other hand Nielsen defines usability as an evaluator of the quality of the user experience while interacting with a web based or traditional software application, and specifies five characteristics: efficiency of usage, ease of learning, memorability, subjective satisfaction and error frequency.
BACKGROUND ON USABILITY ENGINEERING AND HUMANCOMPUTER INTERACTION
Despite the growth of information technology in last 10 years and a growing dependence on computers in all aspects of the human civilization, only recently the user needs have become part of software and interface development. In 1990s, software companies started to address their customer requirements seriously and to design "usability" into their softwares and web-products rather than focusing exclusively on functionality. Usability testing includes studying and designing "ease of use" into a product. Its key element, Human Computer Interaction (HCI), the study of how people interrelate with computer technology and how to make this interface effective, provides the hypothetical basis for applying usability concepts to web applications and computer software interfaces.
Web sites are as best suitable as software to the precepts of HCI; therefore usability engineering can suggest a universal approach to Web design. HCI states that interfaces should meet the following goals:
(1) Provide task support, that is, enable users to achieve their goals and meet their particular needs;
(2) Be usable by making it possible for users to work easily, efficiently and with few errors
(3) Provide an aesthetically pleasant interface design.
A usable or "user-oriented" interface is one that successfully meets these goals. The International Standards Organization (ISO) defines "usability" as "the level to which a product can be used by specified users to attain precise goals with effectiveness, efficiency, and satisfaction in a specified context of use." Applied this concept to Web technology, this means purely that, for the tasks it is designed to support, an interface must be easy to learn, memorize, and execute, and must guide to few errors. The most efficient means of assessing a website's usability is with usability testing, which we shall discuss in more detail later in this thesis report.
WHAT IS WEBSITE USABILITY
Website usability is a significant concept in web design which is from time to time overlooked in the rush to launch a website or software product. In simple words, website usability involves building a site which is easy, amusing, and logical for users, so that they can enjoy using the site and they can operate it to find what they require. This consideration is critically important for companies that want to build brand loyalty and attract customers, as people are turned off by websites which they have trouble using.
If a visitor finds your website easy to use, they are much more likely to turn into a customer. Therefore the purpose of reviewing website usability is to ensure your website is as easy as possible to use, and as such is as effective as possible in turning visitors into customers. If a potential customer finds your website easy to use they are more likely to become a customer.
"Website usability is the ease with which visitors are able to use your website."
The aim of reviewing a website's usability is to ensure your website gives visitors no reason to go elsewhere and consequently sees them make the transition from visitors to customers.
KEY FEATURES
Ease of navigation is one of the key features in website usability. When a site is clearly and modestly laid out, with a logical progression of areas and topics, it tends to appeal to users. A tangled mess of a site is hard to move around on, and it may be challenging for people to access the information and topics they want. If users get frustrated enough, they may give up altogether and take their business elsewhere. Being friendly for search engines is also important to many webmasters, as most people want to attract traffic to their sites.
Efficiency is also one of the most important key features of website usability. It is used to measure that how quickly the site visitors complete their task on a website and how many specific steps are required to complete the task? What elements were preventing or stopping the user to accomplish their goals.
Learnability & Memorability: The former one is used to determine that how quickly and easily the new visitor on the website learn to use it efficiently and the later one is used to find out that how effectively the repeated user use the website.
Design aesthetics are also an important aspect of website usability. If a site is well designed, it is clear, easy to understand, and easy to view. If the design is too cluttered, ornate, or illogical, users may struggle with it, especially if they have visual impairments. A growing number of websites are thinking about visual impairments and other disabilities in the design phases so that sites will be accessible to everyone, not just people with young, healthy eyes. Things like cute visual features which look neat but make it hard for people with screen readers to use a site are being eliminated in favour of more friendly design.
Functionality is another characteristic of website usability of the site. If a website has bugs, broken links, pictures that don't load, and other issues, people will have trouble using it. Nothing frustrates a user more than clicking on a link which leads nowhere, or trying to submit a form which will not go through. If a user does encounter a bug or problem, navigational tools which help the user report the bug and then return to what he or she was doing are critical, to make sure that users know that they are valued, and that site owners find bugs just as annoying as users do.
Error Prevention & Recovery: No website is 100 percent error free. We have to find out If the website implements a design which allows the easy recovery from the errors or not.
User Satisfaction: User satisfaction is heavily biased by the capability to achieve goals. If the user is able to achieve their goals on website with ease and efficiency, they report highly satisfaction. If they encounter problems during accomplishing tasks they will report low level of satisfaction.
There are two methods that can be used to test the usability of a website. They are
Heuristic Evaluation
Eye Tracking Technology
Heuristic evaluation is a discount usability engineering method for quick, cheap, and easy evaluation of a user interface design. Heuristic evaluation is the most popular of the usability inspection methods. Heuristic evaluation is done as a systematic inspection of a user interface design for usability. The goal of heuristic evaluation is to find the usability problems in the design so that they can be attended to as part of an iterative design process. Heuristic evaluation involves having a small set of evaluators examine the interface and judge its compliance with recognized usability principles.
For our Study we have chosen Eye Tracking Technology. The reason why we choose this will be discussed later in this chapter.
EYE TRACKING IN WEBSITE USABILITY
Eye tracking is a technique allowing testers to determine eye movement and eye-fixation patterns of a person.
Eye tracking can be used in both passive and active modes. In usability testing, eye tracking helps website designers to evaluate the usability of their screen layouts. It is an example of passive, "observing" use of eye tracking, because the eye-tracking devices simply monitor eye activity for later study and analysis. Other examples of passive mode are:
• Behavioural scientists can monitor what pilots or control room operators look at when given certain tasks or placed in certain situations.
• Reading specialists can use eye tracking to recognize when a person is reading and when he/she has fixated on a word longer than normal, in order to create a highly individualized reading aid.
• Marketing researchers can determine what features of product advertising and packaging attracts buyer attention.
Eye tracking can also be used to actively direct a computer through the motions of the eyes (active, "control mode"). Some of the examples are:
• Disabled people who cannot use their hands to operate a computer can do so with their eyes, using on-screen keyboards and mouse controllers.
• Hospitals can provide an eye-aware communication program to people who have lost their ability to move and talk, either provisionally or permanently through a terrible accident.
EYE TRACKING, VISUAL ATTENTION AND THE LIMITS OF CONVENTIONAL USABILITY METHODS
First consider the following quotes:
For a long time now there has been a great need for a means of recording where people are looking while they work at particular tasks. A whole series of unsolved problems awaits such a technique (Mackworth & Thomas, 1962, p. 713; emphasis added).
The eye tracking system has a promising future in usability engineering (Benel, Ottens & Horst, 1991, p. 465; emphasis added).
Aggregating, analyzing, and visualizing eye tracking data in conjunction with other interaction data holds considerable promise as a powerful tool for designers and experimenters in evaluating interfaces (Crowe & Narayanan, 2000, p. 35; emphasis added).
Eye-movement analysis does appear to be a promising new tool for evaluating visually administered questionnaires (Redline & Lankford, 2001; emphasis added).
Eye tracking technique has been used for nearly 100 years in psychology, focusing on observing eye movements while reading or looking on the computer screen. When personal computers started to flourish in the 1980's, researchers began to incorporate the field of eye tracking into issues of human-computer interaction. As technological advances such as the Internet, e-mail, and videoconferencing evolved into practicable means of information sharing during the 1990's and beyond, researchers tried to apply eye tracking in order to answer question about usability (e.g. Benel, Ottens & Horst, 1991; Ellis et al., 1998; Cowen, 2001). In these provisions Goldberg and Wichansky distinguish between two groups of readers: eye tracking scientists who apply their work to usability evaluations and usability engineers who try to implement eye tracking into their studies. Evaluating the allocation of visual attention with conventional methods like click analysis, questionnaires or simply asking subjects where they have paid attention to, are limited to those processes which are part of conscious reflection and conscious control. Depending entirely on such methods will lead to a major validity problem, because attentional processes do not exclusively rely on conscious control. They are often controlled beyond subjects' awareness, are therefore not reportable or are simply too fast to be analyzed by mouse movements. In order to test the attentional strength of marketing interventions or to find out where on the screen visual attention is deployed to, it is necessary to apply specific and valid psychological methods.
In the recent years along with other technological advances, eye tracking has become a capable tool in order to reply such questions. The main objective of the eye tracking method is to review the allocation of visual attention on the screen. There is overall no doubt that eye tracking data are an essential prerequisite for the focus of visual attention.
HOW MODERN EYE TRACKING WORKS
In older days eye tracking was done by problematical means, such as physically gluing something to a test user's eyeballs. Newer eye tracking technology works on the same basic principle i.e. focusing a light and a video camera on person's eye. The light helps to figure out in which direction the person is looking. The video camera records the interaction between the user and the system along with some back-end analysis. The first eye tracker used in 1980s in which the user's head was strapped into a fixed position. By doing this, the need of calculating the head movement was eliminated because it always was on the same spot. Though, it was not the pleasant experience for the test participants. However in 1990s, eye tracking equipment was minimised and converted enough to be placed in a headband or a cap. But that doesn't remove the original problem because the head and the device were moving into the parallel positions. This was time consuming, stressful and error prone method because users had to look like dorks and making them sprain their necks and back due to the heavy stuff on their heads.
In 2000s, technology improved to the extent that it's now possible to assign a separate camera to analyse the user's head position in real time. Other cameras are zoomed in to capture the closer view of eyes. Since everybody looks in the same direction with both eyes, the eye tracker figured out its conclusion about where the user is looking by taking the average of the calculations of both the eyes. Other most inventive method used by most modern eye trackers is to bounce a beam of invisible infrared light on the user's face. This wave length is reflected by the retina which helps the eye tracker to identify the position of the users without having to do extreme recognition. Putting all information together, it's quite simple to calculate the direction of a user's gaze. It's even easier to calculate what the user is looking at by finding the intersection between the plane of the computer monitor and gaze direction (a straight line). Some of the eye trackers based on this infrared technology are Tobii Eye Tracking Technology, DynaVox Technology, and EyeTech Digital Systems etc.
The basic idea behind eye tracking is that eye movements can be used to make deductions about user's cognitive processes. An eye tracker follows the user's eye movements by reflecting infrared light onto the eye and then, using a geometrical model, determines the exact gaze point of the user. Remote eye trackers like Tobii T60/T120/T60 XL, allow participants to sit with comfort in front of a screen fitted with a builtâ€in eye tracking device. To nearly all users, the screen will look almost like a normal computer screen, making it a comfortable and common device to work with. Most eye tracking studies aim at analyzing patterns of visual attention of individuals when performing specific tasks e.g. reading, website searching, scanning an image, driving, etc. In these studies eye movements are typically analyzed in terms of fixations (a pause of the eye movement on a specific area of the visual field) and saccades (rapid movements between fixations). This data is usually illustrated using gaze plots which show saccades and fixations or aggregated heat maps which show the amount or length of fixations.
EYE-MOVEMENT METRICS
The main measurements used in eye-tracking research are fixations and saccades (described previously). When the eye is resting on something, it's called a fixation. The eye's rapid movements from one fixation to the next are called saccades. The optical image on the retina blurs so much during these movements that people are effectively blind during a saccade. There are also a multitude of derived metrics that stem from these basic measures, including "gaze" and "scanpath" measurements.
FIXATIONS: Fixations can be interpreted quite differently depending on the context. In an encoding task (e.g., browsing a web page), higher fixation frequency on a particular area can be indicative of greater interest in the target, such as a photograph in a news report, or it can be a sign that the target is complex in some way and more difficult to encode (Jacob & Karn, 2003; Just & Carpenter, 1976). However, these interpretations may be reversed in a search task: A higher number of single fixations, or clusters of fixations, are often an index of greater uncertainty in recognizing a target item (Jacob & Karn, 2003). The duration of a fixation is also linked to the processing-time applied to the object being fixated (Just & Carpenter, 1976). It is widely accepted that external representations associated with long fixations are not as meaningful to the user as those associated with short fixations (Goldberg & Kotval, 1999). Fixation-derived metrics are described in Table 1.
Eye-Movement Metric
What it Measures
Reference
Number of fixations overall
More overall fixations indicate less efficient search (perhaps due to sub-optimal layout of the interface).
Goldberg & Kotval (1999)
Fixations per area of interest
More fixations on a particular area indicate that it is more noticeable, or more important, to the viewer than other areas.
Poole et al. (2004)
Fixations per area of interest and adjusted for text length
If areas of interest are comprised of text only, the mean number of fixations per area of interest should be divided by the mean number of words in the text. This is necessary to separate out: (i) a higher fixation count simply because there are more words to read, from (ii) a higher fixation count because an item is actually harder to recognize.
Poole et al. (2004)
Fixation duration
Longer fixation duration indicates difficulty in extracting information, or it means that the object is more engaging in some way.
Just & Carpenter (1976)
Gaze
Gaze is usually the sum of all fixation durations within a prescribed area. It is best used to compare attention distributed between targets. It can also be used as a measure of anticipation in situation awareness if longer gazes fall on an area of interest before a possible event occurring.
Mello-Thoms et al. (2004);
Hauland (2003)
Fixation spatial density
Fixations concentrated in a small area indicate focused and efficient searching. Evenly spread fixations reflect widespread and inefficient search.
Cowen et al.(2002)
Repeat fixations
Higher numbers of fixations off-target after the target has been fixated indicate that it lacks meaningless or visibility.
Goldberg & Kotval (1999)
Time to first fixation on-target
Faster times to first-fixation on an object or area mean that it has better attention-getting properties.
Byrne et al. (1999)
Percentage of participants
fixating an area of interest
If a low proportion of participants is fixating an area that is important to the task, it may need to be highlighted or moved.
Albert (2002)
Table 1: Fixation-derived metrics and how they can be interpreted in the context of interface design and usability evaluation. References are given to examples of studies that have used each metric.
SACCADES: No encoding takes place during saccades, so they cannot tell us anything about the complexity or salience of an object in the interface. However, regressive saccades (i.e., backtracking eye-movements) can act as a measure of processing difficulty during encoding (Rayner & Pollatsek, 1989). Although most regressive saccades (or "regressions") are very small, only skipping back two or three letters in reading tasks, much larger phrase-length regressions can represent confusion in higher-level processing of the text (Rayner & Pollatsek, 1989). Regressions could equally be used as a measure of recognition value, in that there should be an inverse relationship between the number of regressions and the salience of the phrase. Saccade-derived metrics are described in Table 2.
Eye-Movement Metric
What it Measures
Reference
Number of saccades
More saccades indicate more searching.
Goldberg & Kotval (1999)
Saccade amplitude
Larger saccades indicate more meaningful cues, as attention is drawn from a distance.
Goldberg et al. (2002)
Regressive saccades
Regressions indicate the presence of less meaningful cues.
Sibert et al. (2000)
Table 2: Saccade derived metrics and how they can be interpreted in the context of interface design and usability evaluation. References are given to examples of studies that have used each metric.
SCANPATHS: A scanpath describes a complete saccade-fixate-saccade sequence. In a search task, an optimal scan path is viewed as being a straight line to a desired target, with relatively short fixation duration at the target (Goldberg & Kotval, 1999). Scanpaths can be analyzed quantitatively with the derived measures described in Table 3.
Eye-Movement
Metric
What it Measures
Reference
Scanpath duration
A longer-lasting scanpath indicates less efficient scanning.
Goldberg & Kotval (1999)
Scanpath length
A longer scanpath indicates less efficient searching (perhaps due to a sub-optimal layout).
Goldberg et al. (2002)
Spatial density
Smaller spatial density indicates more direct search.
Goldberg & Kotval (1999)
Transition matrix
The transition matrix reveals search order in terms of transitions from one area to another. Scanpaths with an identical spatial density and convex hull area can have completely different transition values - one is efficient and direct whilst the other goes back and forth between areas, indicating uncertainty.
Goldberg & Kotval (1999); Hendrickson,
(1989)
Scanpath regularity
Once "cyclic scanning behavior" is defined, deviation from a "normal" scanpath can indicate search problems due to lack of user training or bad interface layout.
Goldberg & Kotval (1999)
Spatial coverage calculated with convex hull area
Scanpath length plus convex hull area define scanning in a localized or larger area.
Goldberg & Kotval (1999)
Scanpath direction
This can determine a participant's search strategy with menus, lists and other interface elements (e.g. top-down vs. bottom-up scanpaths). "Sweep" denotes a scanpath progressing in the same direction.
Altonen et al. (1998)
Saccade/fixation Ratio
This compares time spent searching (saccades) to time spent processing (fixating). A higher ratio indicates more processing or less searching.
Goldberg & Kotval (1999)
Table 3 - Scanpath-derived metrics and how they can be interpreted in the context of interface design and usability evaluation. References are given to examples of studies that used each metric.
DIFFICULTIES & UNRESOLVED ISSUES IN EYE TRACKING TECHNOLOGY
Eye tracking technology has many benefits but there are some difficulties and constraints which are also associated with this technology. Some of them are discussed below.
Some persons cannot be eye tracked for physiological reasons: the user may not reflect enough light, or the iris may be too light in colour to be distinguished from the user reflection; the user may be too large or it may be affected by eye lashes or eye lids, making the eye difficult to track; the person may have a wandering eye.
Other persons cannot be eye tracked, for external reasons, such as eyeglasses or hard contacts.
Problems can occur during the eye-tracking process: a person's eyes may dry out during an experiment and become difficult to track. Sometimes a participant can be eye tracked one day and not the next, or half way through a test the eye track degrades to the point that the data collected cannot be used.
While using a remote eye-tracking system, head movement may cause a delay until the eye tracker reacquires the eye, and may also cause loss of calibration. Restraining methods to keep the participant's head stationary may cause the participant to feel awkward and the testing situation to become completely unnatural.
Interpreting eye-tracking data isn't always easy, and can be an issue. Integrating eye-tracking data with data from traditional interviewing and observing methods could be even more challenging.
Unresolved Issues
At the CHI 99 workshop "The hunt for usability: tracking eye movements", a team of participants discussed technical issues with the eye-tracking technology. They recommended a number of issues that were considered to be "the most important unresolved issues in the area of integrating eye tracking in usability testing:
• How to handle excessive volume of data
• Correspondence of eye position and deployment of attention
• Integration of multiple cameras
• Fuse eye, mouse, facial expression, voice input, other data
• Standardize definitions of derived data (e.g. fixations)
• Taxonomy of dependent measures and applications
• Reduce complexity of equipment use and data analysis
TOBII EYE TRACKING TECHNOLOGY
Tobii's eye tracking technology utilizes advanced image processing of a person's face, eyes and reflections in the eyes of near-infrared reference lights to accurately estimate:
the 3D position in space of each eye
the precise target to which each eye gaze is directed towards
Key advantages
Tobii has taken eye tracking technology a significant step forward through a number of key innovations that enable large market applications. Key advantages of Tobii's eye tracking technology are:
Fully automatic eye tracking
High accuracy in tracking
Ability to track all age group
Completely non-intrusive
Good tolerance of head-motion
Tobii conducts research and development into eye tracking applications. Tobii's eye-based interaction technology includes the Tobii eye control engine, a powerful ActiveX-based API for rapid creation of eye control applications in the Windows environment. This allows the users to quickly develop and customize applications to utilize eye gaze as a modality in computer interfaces.
WHY WE CHOOSE TOBII
The Tobii Studio analysis software provides us with an excellent resource for analyzing complex eye-movement data. Eye-movement data is very rich and can be very time-consuming to analyze. Tobii Studio enables us to analyze the data more efficiently and effectively. The research teams are using Tobii X120 Eye Trackers together with Tobii SDK, ClearView and Tobii Studio, all of them offers a complete solution for testing the websites with eye tracking, which perfectly matches to the user needs. The wider screen of the T60 XL Eye Tracker also provides a better opportunity to present unusual stimulus and longer pursuit trajectories. One of the more exciting aspects of the system is the capability to examine eye movement behavior using naturalistic stimuli in the clinic.
The Tobii T60 XL is supplied with Tobii Studio, which is excellent software for display and analysis. The Tobii X120 Eye Tracker allows the user to monitor eye-movements without the participant knowing that usability testers are monitoring their eye-movements. The system is easy to standardize and very unobtrusive.
