Lecture
Usability (from English usability — «convenience and simplicity of use, the degree of ease of use», also convenience of use, fitness for use, ergonomics — the ability of a product to be understood, learned, used and attractive to the user under specified conditions (ISO/IEC 25010); a property of a system, product or service that, when present, enables a specific user to operate the system under specific conditions to achieve set goals with the required effectiveness, efficiency and satisfaction (ISO 9241-210). Usability (from English "usability") testing is the process of evaluating the convenience of use and overall user-friendliness of a product, such as a website, application, software, etc. The goal of usability testing is to identify problems that users may encounter while using the product, and to provide recommendations for its improvement.
The convenience (fitness) of using a system is not limited to how easy it is to operate. In accordance with the ISO 9241 series of standards, this characteristic should be understood more broadly, taking into account the user's personal goals, their emotions and feelings related to the perception of the system, as well as satisfaction with the work. The properties necessary to ensure fitness for use also depend on the task and the environment. Fitness for use is not an absolute concept; it can manifest differently under specific operating conditions.
Web usability of a website the broad goals of usability and the presentation of information and choices in a clear and concise form, the absence of ambiguity and the placement of important elements in the appropriate areas, as well as ensuring that the content works across different devices and browsers. The ultimate goal that the creator of a website wants to achieve is to provide users with the best experience.
˝If a website does not meet the needs of its intended users, it will not meet the needs of the organization providing the website. Website development should be user-centered and should evaluate the evolving design against user requirements˝
The usability testing process usually includes the following steps:
Defining the target audience: Identifying the typical users who will use the product. This may include various age groups, levels of technical literacy, professional skills, etc.
Developing test tasks: Creating tasks that users will perform during testing. These tasks usually simulate typical scenarios of using the product.
Conducting testing: Users representing the target audience perform tasks on the product. It is important to record what problems or difficulties arise for them in the process.
Analyzing the results: Studying the data obtained during testing to identify general trends and specific problems. This may include navigation problems, an insufficiently intuitive interface, long waiting times, etc.
Providing recommendations: Determining what changes and improvements can be made to the product to make it more convenient and friendly for users.
Iterative testing: Developers make changes to the product based on the recommendations, after which repeat testing is conducted to evaluate the effectiveness of these changes.
The goal of usability testing is to improve the user experience, which can lead to increased user satisfaction, increased productivity, and a reduction in the number of errors. Ultimately, a well-designed and user-friendly product can gain a competitive advantage in the market.
Web usability includes a small learning curve, easy content exploration, findability, task efficiency, user satisfaction, and automation. These new components of usability emerged as a result of the evolution of the Internet and personal devices. Examples: automation: autofill, databases, personal account; efficiency: voice command (Siri, Alexa, etc.); findability. The number of sites has exceeded 1.5 billion thus, the need for well-designed websites that best serve their users in an increasingly competitive market is growing. Thanks to good usability, users can quickly find what they are looking for. Thanks to the widespread adoption of mobile devices and wireless Internet access, companies can now reach a global market with users of all nationalities at any time and from almost anywhere in the world. It is important that websites can be used regardless of the language and culture of the users. Most users in developed countries conduct their personal business on the Internet: banking, education, errands, etc., which allows people with disabilities to be independent. Websites must also be accessible to these users.
The goal of web usability is to ensure user satisfaction by minimizing the time a user needs to learn new functions and the page navigation system, allowing the user to efficiently complete a task without serious obstacles, providing the user with simple ways to overcome obstacles, and correcting errors and re-adapting to the website or system and application functions with minimal effort.
«Management and maintenance are important for maintaining usability»
Approach to ergonomic requirements
According to ISO 9241 (Ergonomic requirements for office work with visual display terminals), usability is «the degree 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». Consequently, usability on the Internet can be defined as the ability of web applications to support Internet-related tasks effectively, efficiently and with satisfaction. Effectiveness represents the accuracy and completeness with which users achieve a specified goal. Efficiency is the cost of resources relative to accuracy and completeness. Satisfaction is the comfort and acceptability of use.
Websites and applications must be accessible to all users. ADA compliance plays an important role in the usability of the Internet , providing a trouble-free and pleasant experience. Americans with Disabilities Act of 1990} .
With so many different mobile devices (screen size, brand, etc.), it is very important to consider how users perform their task on a small screen. For a mobile device, the components of Internet usability must be observed. Users should get the same sense of satisfaction and accomplishment as if they were using a desktop computer or laptop.
- See also "Mobile Usability" by Jakob Nielsen.
Not only is the screen different, but nowadays mobile users want something different from desktop users. According to a survey conducted by Google, users need mobile-friendly websites because they use them every day for various tasks, such as research. Moreover, if a website is adapted for mobile devices, users are more likely to return to it, but will quickly leave if it is not. Thus, they need a fast and easy-to-use website that loads quickly, has large buttons and readable text, and offers a way to interact (video, apps, social media and other ways to connect with the company). The three most important things when browsing on mobile devices are location, hours of operation, and contact information. Be sure to include them.
Check the mobility of the website here.
Multilingual websites should offer users the same opportunities, regardless of whether the website is in English, German or Japanese. Websites should display the same way in all languages and on all devices. Changes to the user interface, since the language and characters used, must still provide the various components of usability.
Jakob Nielsen's heuristics are widely used in interface design. It provides expert reviewers with a set of principles for identifying usability problems, and then quickly classifying and evaluating them. This set of heuristics includes visibility of system status, match between the system and the real world, and so on. According to Jakob Nielsen, there are 10 general principles:
The W3C publishes a set of guidelines for the accessibility of web resources, called the «Web Content Accessibility Guidelines» (WCAG).
The second version of WCAG, WCAG 2.0, consists of twelve guidelines formulated according to four principles that web content must adhere to: perceivability, operability, understandability and robustness.
The W3C also provides a detailed checklist for this set of guidelines.
To achieve universal usability of web services, designers and developers must take into account the diversity of technologies, the diversity of users, and gaps in user knowledge.
The diversity of technologies is due to the wide range of hardware, software and network access. People use different hardware and software to access web services. For example, reading a document with a document reader program on a smartphone is different from opening that document with Microsoft Office on a laptop. In addition, opening a web page with a bandwidth of 100 KB/s can cause a failure if it is designed for 2 MB/s. Ensuring usability across different platforms can be a challenging task.
The diversity of users is influenced by many factors, including culture, personality, age, gender, race, ethnicity, disability, literacy, income, skills and knowledge. Taking into account the needs of different groups gives access to more people. For example, providing a high-contrast mode for people with poor color perception will help these people use the web service.
Universal usability means not only meeting the current needs of users, but also building a ladder by which users will be able to use additional features of web services in the future. This gap in user knowledge can be filled by a training section, a help desk, a discussion group, and so on. Designers must be aware of the need for additional help.
Communication between the designer and the client is also a problem, since it can be difficult for the designer to implement what the client had in mind, while the client does not fully understand the amount of time and effort required to create a well-designed website. In addition, it is also important that the designer make suggestions based on the clients' ideas, which are supported by usability evidence/theory/examples and other website features. Constant and open communication is important, as conflicts or misunderstandings can arise between the two parties.
To understand what usability is and what it means, it is important to look at it from the client's point of view.
According to Steve Krug [17], currently digital literacy is quite high and growing year by year, and «the way we actually use the Internet» [17] , has changed.
We have become so accustomed to using the Internet and various websites that we no longer read them, but scan them, because we are usually in a hurry to find something and are so accustomed to web pages that there is no need for us to read them in full, since we can successfully filter and find only the information we need, and read more about it if the information found does not satisfy our needs.
Moreover, we don't care about making the most optimal choice when browsing web pages, but instead choose the options that satisfy our needs - we settle for them. This is again because we are usually in a hurry, and there are no real consequences for choosing the wrong option (for example, clicking the wrong link), since the «Back» button is just one click away to solve the problem. Likewise, there is no penalty for guessing, so weighing the options of which button to click, and whether it will give the desired result, is a waste of time.
Because of this, we don't care enough about understanding what we're doing, as long as we can use the features.
As a result, users may develop unexpected mental models and ways of using the website - different from what was intended. Thus, it is important to test every website and its usability.
Usability testing evaluates the various components of network usability (learnability, efficiency, memorability, errors and satisfaction) by observing how users perform their task. Usability testing allows you to identify the obstacles and errors that users encounter when performing a task. However, testing is not a one-time event, but rather a continuous process. To test a website, we need ways to measure it. We need to analyze the collected data and draw up a plan of improvements that will be implemented later. After successful implementation, the site needs to be tested again and the process repeated once more.
As more and more usability research results become available, this leads to the development of methodologies for improving the usability of the Internet. [18] A number of tools are available on the market for usability testing.
In the context of e-commerce websites, the meaning of usability on the Internet narrows down to efficiency: driving sales and/or completing other transactions important to the business.
Usability on the Internet attracted renewed attention as many early e-commerce websites began to fail in 2000. While fashionable graphic design was considered indispensable for a successful e-business application during the emergence of the Internet in the 1990s, the leading figures of web usability said the exact opposite was true. They advocated the KISS principle (keep it simple, stupid), which proved effective in capturing the end user's attention
There are two main ways to assess the convenience (fitness) of product use
Direct assessment is addressed in the ISO 9241-11 standard, which proceeds from the fact that the ergonomics of a system depend on all indicators affecting the operation of the system in real conditions, including both organizational indicators (for example, labor skills, location or appearance of the products) and individual differences between users, for example, in cultural level and preferences. Such a broad approach has its advantages, which consist in focusing on real goals when creating products, the main one of which is to satisfy the needs of real users performing real tasks in a real technical, physical and organizational environment.
Indirect assessment is addressed in the ISO/IEC 25010 standard, which describes the following sub-characteristics of usability:
In most general-language sources, the concept of ergonomics coincides with the concept of convenience (fitness) of use, for example
Ergonomics (from Ancient Greek ἔργον — work and νόμος — «law») — fitness for use (Ideographic Dictionary of the Russian Language) .
Ergonomics — the presence of conditions and opportunities for easy, pleasant, unburdensome use of something or the satisfaction of certain needs and requirements (Large Explanatory Dictionary of the Russian Language) .
The Soviet Military Encyclopedia defines ergonomics as follows:
Ergonomics — the rational distribution of functions between the human operator and technical devices at all stages of the use of combat equipment .
The well-known designer Jakob Nielsen proposed a set of 10 heuristics, or principles of interaction design .
Visibility of system status
The user should always know what is happening, receiving appropriate feedback within a reasonable time.
Match between the system and the real world
The system should «speak the user's language», using terminology and concepts familiar to them, rather than «system-oriented» language.
User control and freedom
Users often choose system functions by mistake and should have a clearly visible «emergency exit» from the undesired state of the system, not requiring complex dialogues. Undo and redo functions should be supported.
Consistency and standards
Users should not have to wonder whether different words, situations or actions mean the same thing. It is also necessary to follow the conventions adopted for a given platform.
Error prevention
A well-thought-out design that prevents a problem from occurring at all is better than the best error messages. Either the very conditions that cause errors should be eliminated, or they should be detected and the user warned of the upcoming problem.
Recognition rather than recall
Minimize the load on the user's memory by explicitly showing them objects, actions and options. The user should not have to remember information from one part of a dialogue that will be needed in another. Instructions for using the system should be visible or easily retrievable wherever possible.
Flexibility and efficiency of use
Accelerators (means of quickly executing commands), which a novice may not even notice, can often speed up interaction for an experienced user. Therefore, the system should satisfy both inexperienced and experienced users. It should be possible to customize frequently used operations to suit oneself.
Aesthetic and minimalist design
The interface should not contain information that the user does not need or that they may need only rarely. Every extraneous element of a dialogue takes attention away from the elements that are actually needed.
Help the user recognize and correct an error
Error messages should be written in plain language, without codes, clearly stating the problem and offering a constructive solution.
Help and documentation
Although it would be better if the system were usable without documentation, it is still necessary to provide help and documentation. The information should be easy to search, correspond to the user's task, describe a specific sequence of actions, and should not be too large.
There are many methods for evaluating usability. Some methods use user data, while others rely on usability experts. There are methods for evaluating usability at all stages of design and development, from product definition to final design modifications. When choosing a method, consider cost, time constraints and feasibility. For a brief overview of the methods, see the Comparison of Usability Evaluation Methods section, or keep reading below. Usability methods can be divided into the subcategories below.
Cognitive modeling involves creating a computational model to estimate how long it takes people to complete a given task. The models are based on psychological principles and experimental research to determine the time of cognitive processing and motor movements. Cognitive models can be used to improve user interfaces or to predict problematic errors and pitfalls in the design process. Here are some examples of cognitive models:
Parallel design
In parallel design, several people create an initial design from the same set of requirements. Each works independently and, upon completion, shares concepts with the group. The design team reviews each solution, and each designer uses the best ideas to further improve their own solution. This process helps generate many different, diverse ideas and ensures that the best ideas from each design are integrated into the final concept. This process can be repeated several times until the team is satisfied with the final concept.
GOMS
GOMS stands for goals, operators, methods and selection rules . This is a family of methods that analyze the usage complexity of interactive systems. Goals are what the user needs to achieve. An operator is an action performed to achieve a goal. A method is a sequence of operators that achieves the goal. Selection rules determine which method satisfies the stated goal, depending on the context.
Human processor model
Sometimes it is useful to break a task into parts and analyze each aspect separately. This helps the tester find specific areas that need improvement. To do this, it is necessary to understand how the human brain processes information. The human processor model is shown below.
Numerous studies have been conducted to estimate the cycle time, decay time, and performance of each of these processors. The variables that affect them can include the subject's age, aptitudes, abilities, and environment. For a younger adult, reasonable estimates are:
| Parameter | Mean | Range |
|---|---|---|
| Eye movement time | 230 ms | 70–700 ms |
| Half-life of visual image storage | 200 ms | 90–1000 ms |
| Perceptual processor cycle time | 100 ms | 50–200 ms |
| Cognitive processor cycle time | 70 ms | 25–170 ms |
| Motor processor cycle time | 70 ms | 30–100 ms |
| Effective working memory capacity | 2 items | 2–3 items |
Long-term memory is thought to have infinite capacity and infinite decay time. [16]
Keystroke-level modeling
Keystroke-level modeling is, in essence, a less complete version of GOMS, which makes simplifying assumptions to reduce computation time and complexity.
These usability evaluation methods involve observing users by an experimenter, or testing and evaluating the program by an expert reviewer. They provide more quantitative data, since tasks can be timed and recorded.
Card sorting
Card sorting is a way to engage users in grouping information to test the usability of a website. Participants in a card sorting session are asked to organize the content of a website so that it makes sense to them. Participants review items from the website and then group these items into categories. Card sorting helps to learn how users think about the content and how they would organize information on the website. Card sorting helps build the website's structure, decide what to put on the home page, and label the home page categories. It also helps ensure a logical organization of information on the site for users.
Tree tests
Tree testing is a way to evaluate the effectiveness of the top-down organization of a website. Participants are given a «find» task and then asked to browse through successive text lists of topics and subtopics to find a suitable answer. Tree testing evaluates the findability and labeling of topics on the site, separately from navigation controls or visual design.
Ethnography
Ethnographic analysis originates from anthropology. Field observations are conducted at the location of a potential user, and they track work artifacts, such as notes, desktop items, shortcuts, and items in trash bins. These observations also capture the sequence of work and breaks that define a user's typical day.
Heuristic evaluation
Heuristic evaluation is a usability engineering method for finding and evaluating usability problems in a user interface design as part of an iterative design process. It involves having a small set of evaluators examine the interface and use recognized usability principles (the «heuristics»). It is the most popular of the usability inspection methods, as it is fast, cheap and easy. Heuristic evaluation was developed to help with the design of computer user interfaces. It relies on expert reviewers who detect usability problems and then classify and rate them against a set of principles (heuristics). It is widely used because of its speed and cost-effectiveness. Jakob Nielsen's list of ten heuristics is most commonly used in industry. These are the ten general principles of user interface design. They are called «heuristics».
Thus, by determining which rules are violated, the usability of the device can be determined.
Usability inspection
Usability inspection is a review of a system based on a set of guidelines. The review is conducted by a group of experts well versed in usability concepts in design. The experts focus on a list of design areas that have proven problematic for users.
Pluralistic walkthrough
Pluralistic walkthroughs are meetings where users, developers, and human factors people meet together to discuss and evaluate a task scenario step by step. The more people review the scenario for problems, the more likely they are to be found. In addition, the more interaction within the team, the faster usability issues are resolved.
Consistency inspection
In a consistency inspection, experienced designers review products or projects to ensure consistency across multiple products, to make sure they work in the same way as their own designs.
Activity analysis
Activity analysis is a usability method used in the preliminary stages of development to get a sense of the situation. It involves the researcher observing users as they work in the field. Also called user observation, it is useful for determining user requirements and studying the tasks and subtasks currently in use. The data collected is qualitative and useful for identifying the problem. It should be used when you want to highlight what is needed, or "What do we want to know?"
Usability testing — a study performed to determine whether a given artificial object (such as a web page, user interface, or device) is convenient for its intended use. Thus, usability testing measures the usability of an object or system. Usability testing focuses on a specific object or a small set of objects, while human-computer interaction research in general — formulates universal principles.
Usability testing — a method of evaluating the convenience of a product in use, based on engaging users as testers, and summarizing the conclusions obtained from them.
When testing many products, the user is asked, under «laboratory» conditions, to solve the main tasks for which the product was designed, and is asked to voice their comments while performing these tests.
The testing process is recorded in a protocol (log) and/or on audio and video equipment — for the purpose of subsequent, more detailed analysis.
If a usability test reveals any difficulties (for example, difficulties in understanding instructions, performing actions, or interpreting the system's responses), then the developers should refine the product and repeat the testing.
Observing how people interact with a product often makes it possible to find more optimal solutions for it. If a moderator is used during testing, their task is to keep the respondent focused on the tasks (but without «helping» them solve these tasks).
The main difficulty after conducting a usability testing procedure is often the large volume and disorderliness of the data obtained. Therefore, for subsequent analysis, it is important to record:
All these data streams must be synchronized by time codes so that they can be correlated with each other during analysis.
Along with the moderator, observers often take part in the testing. As they discover problems, they make their own notes on the progress of the testing so that these can later be synchronized with the main recording. As a result, every significant fragment of the test recording ends up commented on in the observer's notes. Ideally, the facilitator (that is, the moderator) represents the developer, the observers represent the customer (for example, the publisher or distributor), and the test participants represent the end user (for example, the buyer).
In addition to the above, there is another approach to checking ergonomics: for the task given to the user, an «ideal» scenario for solving this task is developed. As a rule, this is the scenario the developer had in mind. As users perform the task, their deviations from the intended scenario are recorded for subsequent analysis. After several iterations of refining the program and subsequent testing, an interface that is satisfactory from the user's point of view can be obtained.
Often, it is not users but usability experts who are brought in to conduct usability testing, and they perform a usability expert review
The expert evaluation report — one of the main results of the expert usability evaluation of a system. The report lists all the identified shortcomings in the product's ergonomics and gives recommendations on how to eliminate them. The report also lists the positive aspects of the system's interface. Ideally, the expert evaluation report should be accompanied by wireframes that already reflect the recommended fixes.
Three stages, during which the existing product is analyzed and recommendations are prepared for improving its interface.
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