This essay has been submitted by a student. This is not an example of the work written by our professional essay writers.
This literature review discusses two papers that evaluate the usability of mobile websites from two different perspectives - one considers the impact of the prevailing environmental conditions of use on the usability of a mobile website while the other considers the impact of mobile device constraints (such as the smaller screen) on usability by comparing the levels of user satisfaction when viewing a website on a mobile device as opposed to viewing it on a desktop.Together, these two papers provide insight into the device and environmental factors that affect usability when using mobile devices to access the internet.
The ISO defines usability as the "extent to which a product can be used by specified users to achieve specified goals with effectiveness, efficiency and satisfaction in a specified context of use". Nielsen states,"On the web, usability is a necessary condition for survival." With an ever increasing number of websites providing goods and services on the internet, users are more likely to move on to another website rather than try to understand a website interface where they face some difficulty . As such, the success of a website depends heavily on how usable the website is .
Traditionally, users access websites on desktops, laptops, or other static terminals. However, in recent years, there has been an explosion in the usage of internet-enabled mobile devices. The emergence of smartphones and tablets has caused a surge in the number of people who use the Interneton the go. In its 2010 Internet Trends report, Morgan Stanley, a financial services provider, estimates that by 2015, the number of mobile Internet users globally will surpass that of desktop users. Unfortunately, the constraints of mobile devices such as smaller screen sizes and limited input methods reduce the usability of websites that are not optimized for mobile devices.
For websites to be successful on the mobile platform, it is important that their usability on such devices is optimized . This can be facilitated by employing usability evaluation techniques during the design process of these mobile websites to reveal problems that may plague users and resolve them.
In this literature review, the first paper that is examined is a 2010 conference paper, "An Empirical Assessment of Environmental Factors that Influence the Usability of a Mobile Website" written by Alexandros S. Tsiaousis and George M. Giaglis. This paper describes a study that investigates the impact of the environment where a user of a mobile website resides on the usability of the website. The second paper is also a conference paper written by Sujan Shrestha and titled "Mobile Web Browsing: Usability Study". This paper documents a usability study of websites that compares the usability problems faced on mobile devices against those that are encountered on desktop devices. At the end of this literature review, it should become clear from the analysis of these two papers, the environmental and device considerations that should be factored into the design of mobile websites to optimize their usability.
2.1 Impact of the environment on usability
Tsiaousis and Giaglis  examined the influence of the environment of a mobile website user on the usability of the website. They studied the variations in usability criteria such as efficiency, effectiveness and satisfaction as the conditions of use were altered in a laboratory environment. In developing the model for their study, they derived the following hypotheses covering the effects of auditory distractions, visual distractions, social distractions and situational mobility:
The variance of auditory distractions will have a negative effect on mobile web usability
The semantics of auditory distractions will have a negative effect on mobile web usability
The luminosity of visual distractions will have a negative effect on mobile web usability
The motion of visual distractions will have a negative effect on mobile web usability
Proximity of nearby people will have a negative effect on mobile web usability.
The effect of visual, auditory and social distractions on mobile web usability will be positively influenced by situational mobility
Testing of the hypotheses was conducted in a two-step empirical study consisting of a pilot phase and a main experimental phase. The pilot phase had thirty participants who were asked to perform four tasks on a mobile website while the environmental conditions in the laboratory were altered by introducing sounds, changing lighting levels and having people walk around the laboratory. While analysing the data from this phase, the perceived workload of each user was factored into the statistical process, and the variance due to it was removed. Results from the pilot study showed that the environmental factors investigated all had significant effects on the efficiency and effectiveness of a mobile website but not on the level of satisfaction reported by the participants. In the main experiment (comprising of sixty-four participants) it became evident that the variance of auditory distractions did not have a significant effect on effectiveness or efficiency, contrary to conclusions of the pilot study. All other findings from the main experiment corroborated the findings of the pilot study.Tsiaousis and Giaglis  concluded that "the number of errors and the time needed to complete a task, when browsing a mobile website, are significantly affected by the conditions of use".
This study employs a very sophisticated experimental model and design, and clearly documents the statistical methods used to analyse the data and draw conclusions. This greatly enhances the credibility of the study.
It is important to note that the study does not show any significant correlation between the conditions in the environment of use and user satisfaction. This suggests that the factors that determine user satisfaction may be non-environmental in nature or perhaps that other environmental factors, which were not considered in the study might be the determinants of this aspect of usability.
Furthermore, the study is based on the ISO definition of usability. While this is a suitable foundation to use for the study (being a standard), important aspects of usability as defined by Nielsen , which include learnability (how easy is it for users to accomplish basic tasks the first time they encounter the design) and memorability (when users return to the design after a period of not using it, how easily can they re-establish proficiency), are not investigated in the study. Further research into the impact that the environment may have on these two aspects of usability is required.
From the data and conclusions of the study , it can be inferred that mobile websites are not ideal for performing immersive tasks that require prolonged periods of concentration such as reading books or watching videos. Instead, they are more suited to tasks that are very goal oriented such as finding a telephone number for a service. This is so because the environment of the mobile Internetuser may not always be suitable for performing immersive tasks (due to the presence of the distractions investigated by Tsiaousis and Giaglis). This is an area where further study is required.
2.2 Impact of mobile device constraints on usability
Shrestha  compared the level of satisfaction of users when viewing a website on a mobile device as opposed when viewing the website on a desktop. This evaluation was carried out in a controlled laboratory experiment where twelve participants were given four tasks to perform on a mobile device and on a desktop simultaneously. It was expected that the tasks would all be easy to accomplish in a desktop browser but have varying difficulty levels when using a mobile browser. In a mobile browser, task 1 should be very easy, task 2 should be easy, task 3 should be difficult and task 4 should be very difficult to perform. Participants were asked to think-aloud while performing each task. The comments were recorded along with the time it took to complete a task, whether the task was completed or not and how many mistakes way made in the process. User satisfaction was measured using a questionnaire which was administered after tasks were completed.
The study found that the participant encountered lots of difficulty when trying to complete tasks with the mobile browser. Some of these were attributed to the small size of the device screen (which made websites to require lots of scrolling to reveal information), and awkward input methods (which made mistakes common and difficult to correct). As the difficulty of the tasks increased, the number of participants that successfully completed tasks on the mobile device decreased from 13 (in task 1) to 3 (in task 4). At least 11 participants completed all tasks on the desktop. From the total time it took to complete all four tasks on both the mobile device and the desktop, 80% of that time was spent performing tasks on the mobile device. The overall satisfaction score for web browsing on a mobile device was 3.5 on a 5-point scale.
Shrestha concludes by acknowledging that it may not be possible to achieve the same user experience on desktop and mobile browsers. He goes on to propose guidelines that web authors should follow to help improve the user experience for visitors that use their websites on mobile devices.
Closer examination of this study  raises some questions about the experimental process that was used to gather data. Participants were asked to perform tasks on the desktop first before attempting the same task on a mobile browser. In the experiment design, the tasks were chosen so that they were all easy to complete in a desktop browser, but they had increasing difficulty when using a mobile device, with difficulty ranging from very easy (task 1) to very difficult (task 4). This introduces the potential of biasing the participant's view of the mobile interface since the experiment design causes a transition from a platform that is easier to use (desktop) to one that is more difficult (mobile). This potential bias is not taken into consideration when interpreting the results of the experiment.
Also, it is not clear from Shrestha's study whether the websites that were being viewed by the mobile browser had been optimized for mobile devices or not. If they were optimized for mobile use, then the observations of the study may be down to changes made as part of this optimisation process, and further research may be required to investigate this. However, if the websites have not been optimized for mobile use, then this study demonstrates that websites built for the desktop are not always suitable for use on a mobile device. As such, it is important to create mobile friendly versions of websites to improve user experience and usability.
Increasing interest from different human computer interaction (HCI) groups worldwide will continue to drive research into the usability of mobile devices and the factors that affect it. The key findings of the papers reviewed open more avenues for such research to be conducted. Tsiaousis and Giaglis concluded that the usability of a mobile website is affected by the environment of the website's user. This raises an interesting question: "What are the optimal environmental conditions for using mobile websites"? This is a question that can be answered by carrying out more research. Shrestha  concluded that that it may not be possible to achieve exactly the same user experience on mobile and desktop browsers, however he proposed design guidelines that can improve the usability of websites on mobile devices. Further research could be conducted to clearly assess the benefits of following these guidelines. It will also be interesting to repeat Shrestha'sexperiment  with more sophisticated mobile devices such as the iPhone or Android powered smartphones to see how technological advancement affects the results of the study.
The two studies reviewed in this paper reveal two important facets to evaluating the usability of websites on mobile devices. These are the environmental factors and the device constraints. Giving due consideration to these aspects early on in the design process of a website can greatly improve the usability of the end product of the process and lead to enhanced user experience.
Report comprises 2045 words as counted with Microsoft Word, excluding the bibliography.