Background and Objectives: The user interface of libraries' websites has a decisive role in optimal performance, and libraries can, when they can, have a good performance so that users can communicate with them. In this research, from the viewpoint of library and information professionals, and from the point of view of compliance with the Nielsen ratings, it has been examined whether these criteria have been addressed in the design of the UI web site. The purpose of the present study was to evaluate the interface of the National Book Web site of the Islamic Republic of Iran and the level of compatibility of this website with Nielsen's components in a revealing approach.
Methodology: The present study was a survey based on revelation evaluation. Nielsen's Revelation Assessment was first described in 1990 at the Human-Computer Interaction Conference, which included the use of a small set of evaluators to check the user interface environment and to judge that the user interface features are matched with pre-defined check log criteria. Simple random sampling has been used to choose, but considering that in the user interface studies with an opposite approach, it is better to use expert data. In this research, two main criteria were the criterion for selecting the evaluators. Therefore, 37 individuals were selected randomly, which had two conditions: 1. having a minimum undergraduate degree in librarianship and apprenticeship; 2. Understanding the concept of the user interface. Cranach’s alpha coefficient was used to assess the validity of the check list. The results obtained with 77 questions on the 37 users showed that its alpha coefficient is equal to 0.96, which is a high coefficient. In order to assess the validity of the check list, Content validity method was used in this study.
Findings: In this research, the pattern of revelation that has been identified by numerous studies as a valid universal model for measuring the user-environment utilization has been used to evaluate the user interface environment. The results of the study showed that the degree of compliance of the interface with the " The clarity and feasibility of the system", " the correspondence between the system with the real world", " stability and consistency", " aesthetic aspects and simple design", " recognition instead of reminding messages ", the components of "user control and release", "helping the user to prevent and correct errors", "flexible and system efficiency", "guidance and documentation" are modest, and the level of compliance with the "error prevention" component is very low. Also, the results of the evaluation indicate that on the website of the National Library of Iran, the criterion of control and freedom of action of the user of the website, with 37.84 percent of the criteria, is more consistent with the criteria than the other components and the criterion of error prevention with a minimum of 19.5 percent compliance is the least consistency.  The Nielsen component has ten components. To further benefit from the website of the National Library of Iran, the problems in the web interface that interfere with the users' perception should be identified so that designers of the environment try to resolve their work problems. Considering that in this research, it has been attempted to review the problems of the system by observing all the problems of revelation, it is still possible that there would be problems that the evaluators have left behind. One of the problems found on this site is the bustle and confusion of the UI page. It is not possible to define a different user interface for specific user groups. Data analysis showed that the interface of the website interface of the National Library of Iran with 10 components of Nielsen is generally higher than the average. This website did not have a desirable standard on some of the Nielsen model.
Discussion: The review of the findings of the study on the degree of compliance with the criterion of visibility of the status of the system suggests that users believed that the website of the National Library of the Islamic Republic of Iran will alert them to a great deal about what is happening through appropriate feedback. Also, regarding the compatibility measure between the system and the real world, the result showed that the user interface of the National Library website is largely consistent with this criterion. It seems that the user-interface designers of the National Library of the Islamic Republic of Iran website has been working more towards alignment between the system and the real world. The goal of each site is to help users to interact more with the system; therefore, compliance with this criterion is the focus of attention on the user and his needs. Web site control and users’ freedom of action has a special place in the user's minds, which attracts them and creates interest in them, increases user interaction and facilitates user interaction. The status of this benchmark is modest on the website of the National Library. Considering the importance of the flexibility and system efficiency, it seems that the designers of the website of the National Library of the Islamic Republic of Iran should place more emphasis on the components of the "possibility of color change", in specific cases by the user and "the possibility of personalization of the way information is displayed" in order to reach the desired level in terms of the "flexibility and system efficiency" criterion. Given the importance of benchmarking user assistance in identifying and correcting errors, the National Library website designers need to focus more on the components of helping users identify errors and fix them, informing users of possible errors and applied issues, so that this criterion lead to the expected and desirable situation for users. In the "user control and freedom" criterion, it is not possible to define a different user interface for specific user groups, as well as non-personalization of displaying existing information.