The World Wide Web is a place where people can shop, read articles, search for information of all kinds. Like other activities that are carried out by people offline, browsing the Web involves very complex cognitive processes. According to the Cognitive Load Theory, the human cognitive capacity is limited to processing a few pieces of information at a given time, because the cognitive resources available during the execution of a task are limited too. Many authors have pointed out that browsing the Web generally implies a high cognitive load.
Interestingly, recent research studies have shown that it is possible to decrease the cognitive load during Web browsing by following specific Web design rule sets and guidelines. Despite this knowledge and the potential relevance of the topic, at the best of our knowledge no study has yet investigated how specific task have an impact in terms of cognitive load and user experience. There is also a lack of knowledge on how web design techniques can actually reduce cognitive load.
On the basis of these observations, the proposed study has two main objectives: (1) to investigate the user experience while performing comprehension task on the Web through the adoption of a real-time multi-level assessment, with particular attention on cognitive load; (2) to test the relationship between specific aspects of web design and users experience. The experimental design and protocol of the study will be presented and discussed.
Like many other activities that are carried out by people “offline”, browsing the Web is a very complex cognitive process, especially for the presence of a number of stimuli that must be processed by the human brain. Tasks like reading articles, online shopping and information retrieval require the correct integration of different stimuli and the proper functioning of different cognitive abilities (e.g.: working memory, attention, perception, etc.). Research literature shows that human cognitive capacity can only process a few elements of information at a given time because the cognitive resources available during the execution of a task are limited and they are used selectively and limited towards achieving a specific goal [1, 2, 3]. The Cognitive Load Theory is based on the idea that the intervention of cognitive processes that are closely connected to the memory happens while processing information or performing a task .
A heavy cognitive load may hinder information processing, perception of stimuli and learning intended as study and memorization, particularly during complex activities that require to process a lot of information . Some recent studies [4,5] have pointed out that the Web generally requires a high cognitive effort and, therefore, it is often the cause of cognitive load increase [6, 7]. Therefore, in terms of cognitive load theory, in order to maximize usability and accessibility of a website it is important to minimize cognitive effort, taking the role and limitations of working memory into account. Recent studies have pointed out that the Web imposes a high cognitive load, that increases when web pages become more difficult to use or to understand [4, 5, 6, 7].
Some studies have also demonstrated that is possible to decrease the cognitive load of Web browsing by following some specific rule sets and guidelines [8, 9, 10]. Some of them derive from the application of the cognitive load theory, highlighting how the crucial element to ensure that a website would be easy to use for visitors is the simplicity and the sole presence of essential elements [8,10]. Dumas and Redish  observed that “usability means that people who use the product can perform their tasks in a simple and fast way”. This includes the presentation of information in a clear way, so that users browsing a website would not lose too much time in trying and finding what they need.
There are many similarities between the principles of usability of websites and of Cognitive Load Theory. Usability also requires simplicity, meant as the removal of all unnecessary items . Pages should be consistent in terms of elements and layouts . In addition, there is general consensus about usability improving accessibility for various categories of users . Accessibility is defined as “the extent to which an environment, product, or service removes barriers and allows equal access to all components, irrespective of characteristics and difficulties/disabilities”; in our case the environment is the Web itself . For example, some parameters to be considered for accessibility for people with dyslexia are: text size; line spacing; words per line; font; alignment; color of the background; paragraph spacing [16, 17, 18]. Finally, it is important to consider a visitor’s satisfaction of a Web site (e.g. the fact that a person can find the page easy to use); this increases the intrinsic motivation of the visitor to continue to use this Web site .
However, the design of a Web site that is appealing and that respects the principles of usability represents a challenging task because there are many elements to consider, including simplicity, consistency within and between pages, the layout of the page, ease of navigation . A recent study  found out that the clarity, organization, simplicity, structure, adequate and attractiveness of appearance are the most important aspects that must be met by Web based learning systems.
Despite this knowledge and the potential relevance of the topic, at the best of our knowledge no study has yet investigated how specific tasks (e.g.; comprehension, online shopping, etc.) have an impact in terms of cognitive load and user experience, specifically if combined with appropriate web design techniques and recommendations.
On the basis of these observations, the proposed study has two main objectives:
• to investigate user experience and cognitive load during web browsing through the adoption of a real-time multilevel assessment;
• to verify the relationship between features in terms of site’s Web design (e.g. layout, degree of interaction, usability, etc.) and the users experience.