Human-centred design in 2026: user research, usability and accessibility
Current framework for user research
The principles in this module remain useful, but human-centred design is now practiced throughout the product life cycle rather than as a single usability test before launch. ISO 9241-210:2019, confirmed as current in 2025, frames human-centred activities across the life cycle of interactive systems.
- Research continuously: connect discovery, prototypes, implementation and live-service evidence to explicit research questions and product decisions.
- Recruit for diversity: include likely users with different abilities, digital skills, languages, devices and contexts; document who was not represented.
- Protect participants: obtain informed consent, collect only necessary data, define retention and deletion, secure recordings and allow withdrawal.
- Combine methods: interviews and observation explain behavior, usability tests reveal task barriers, and analytics or experiments measure patterns at scale; none is sufficient alone.
- Accessibility is both research and conformance: test with disabled people and assistive technologies, then combine those findings with standards such as WCAG.
- Human-AI interaction: evaluate incorrect outputs, uncertainty, automation bias, explanations, user control, recovery and escalation, not only whether a generated answer looks plausible.
The ROI ratios quoted later come from older literature and illustrate an argument for early usability work; they are not a guaranteed financial return. Define current success measures such as task completion, error recovery, accessibility, support demand, trust and retention for each product.
Current references: ISO 9241-210:2019, W3C guidance on involving users and participant data and privacy guidance.
1.Introduction
We already know that, although technology has always been developed by technologists, technology developers are not the recipients of the products they themselves create, but people with different levels of knowledge about it. Without However, it has been common in the development of technology to place more emphasis in technical issues than in people, that is, in potential users of the application we are designing (Norman, 1990).
In this fact lies the main argument in favor of studying to users when developing a product or service based on an interactive system. Why is it necessary to study users? The reason is very simple: by far that we like to make the most of our creativity and innovative capacity as developers or designers when addressing the challenge of creating a new product or service based on an interactive system, success in its implementation, Whatever its characteristics, it will not be based on the innovative nature or the new functionalities from a technical point of view, but rather that their use is satisfactory for the people who end up acquiring and using it.
Many times, conducting studies with users is waived due to the increase in the initial investment of the product that these represent. However, cost reduction associated with the introduction of usability aspects in product design is more than proven: not only are production and maintenance costs reduced and support and use, but it considerably increases the quality of the product (Lorés, Granollers and Lana, 2002). Indeed, if we use information from studies with users when developing products, we will have guaranteed approximately 10:1 to 100:1 return on investment (Donahue, Weinschenk and Nowicki, 1999).
For these reasons, the study of potential users at the time to design any technological product is basic. So, in this teaching material we will learn the procedures for carrying out studies with users. We will learn how to design them and execute them, how to analyze the information obtained and how to apply the results in product design, especially with regard to the impact on interaction with the user: we are referring to two basic elements, the functionalities of the interactive product, on the one hand, and to the user interface, on the other.
However, before we begin to delve into the procedures basics of user studies, we will introduce various important concepts: we will define briefly what we mean when we talk about human-computer interaction, discipline scientific from which users and their interaction are studied with technological elements; the user-centered design perspective and the usability, concepts that refer to the importance of user studies to improve interactions with different devices and technological interactions, and the user interface, a term that refers to the different surfaces of communication between technology and the user. These surfaces are, therefore, the objects on which which we are going to mainly apply the knowledge we obtain from users that we study.
Index
1.1.Interaction person-computer
Human-computer interaction is the scientific discipline that, just like its name indicates, is responsible for studying the interactions between people and new technologies of information and communication. The Association for Computer Machinery (ACM) defines human-computer interaction as "that discipline related to design, the evaluation and implementation of interactive computer systems for use by human beings and with the study of the most important phenomena with which that is linked."
Halfway between computer science and the human sciences, it is of a discipline that is nourished by the knowledge that comes from both. Using knowledge What psychology and its different disciplines give us about people, such as social psychology, organizational psychology or cognitive psychology, but also other human sciences such as sociology, anthropology or ergonomics, interactions between users and new technologies are studied to reverse in a substantial improvement in the design of the applications.
Especially relevant for studies with users, which are the object of study of human-computer interaction that we are going to work on in this material didactic, are the theoretical and methodological knowledge that comes from the sciences human.
Specifically, psychology is the science that studies the human behavior. If divided into different disciplines, among which we are interested in highlighting:
The cognitive psychology. Study the processes that occur in individuals when processing information and knowledge. Such important issues that must be taken into account when of designing an interface such as perception, attention or memory are studied from cognitive psychology. The study of individual and collective construction of knowledge is also one of its most important objectives, which has special interest in applications of e-learning and technologically mediated cooperative work.
The social psychology It is the discipline that studies the person in relation to their social context. This knowledge has been shown to be basic to understanding the success of certain products technological and the failure of others (for example, it is easy from social psychology understand the success of games online among male adolescents). Furthermore, the social psychology also contributes very useful methodological tools to collect information about users, both quantitative (surveys and tests) and qualitative (interviews, focus groups and participant observation), as we will see later in this same material.
On the other hand, the organizational psychology studies the relationships and interactions that occur in organizations and at work, a knowledge that is essential for us to design applications that support the different tasks that people carry out in a work environment.
Related to the latter, it is worth mentioning the importance of the ergonomics as a science that studies the interactions between people and the objects to which that we use on a daily basis. Traditionally, ergonomics began by studying how to improve the conditions and quality of life of people in the contexts work, although he later expanded his field of study to leisure contexts. and domestic rest. Within the study of work conditions and prevention of occupational risks, the recommendations have been especially relevant on the use of data display screens; However, the ergonomics part What contributes the most to user studies is undoubtedly cognitive ergonomics. This discipline aims to adapt all those devices that affect the cognitive processes of individuals, so that its use is comfortable, effective and satisfactory. And indeed, the user interface constitutes a very important object of study in this field (Cañas and Waerns, 2001).
Finally, and very synthetically, we could define the sociology as the science that studies societies and anthropology, like the science that studies cultures; cultural and social issues are keys to understanding the reason for the explosion of application implementation based on new information and communication technologies. Furthermore, the ethnomethodology, which is the methodological perspective used by anthropology for the study of communities and people in their daily lives, it is of great importance in the study of the use of technological applications by people in its usual context.
1.2.What do we understand by usability?
Usability is the concept that is most used today to refer to those features that make an application easy to use and intuitive when learning to use.
Gould and Lewis (1985) have described usability as the degree to which which one application:
It's easy to learn.
Contains the functionality necessary for the user to complete tasks for which it has been designed.
It is easy and pleasant to use.
In general terms, there are various recommendations What should we take into account if we want a product or service based on a system interactive is effective, satisfactory and easy to use:
Whenever possible, we should conduct user studies before thinking about the design of a product or service. If this is not possible, we must base the design in previous studies with users of similar applications. Another alternative is including potential users in the creative design process is what is known as participatory design.
We must carry out evaluations with users in all phases of development that are possible for us. At a minimum, we should conduct a user evaluation before preparing the final version of the product.
The final result should be a product that is easy to learn and familiar to the user. user. In order to contemplate these aspects, it is essential to study the users, to be possible in your everyday context. To avoid important changes that result In a loss of product familiarity, it is also important to program the application in a scalable way, so that we can easily introduce changes. This us will allow improvements to be made to the product even once it is marketed without having to carry out substantial modifications. Thus we will considerably increase the consistency of the product; Furthermore, to enhance this familiarity we must also be consistent in the use of style guides and standards look and feel.
Another basic issue in usability is response time; always we must take into account so that a usability problem does not ruin the efforts that we have invested in obtaining a good design.
On the other hand, we must reduce as much as possible the cognitive work that the application user demand; It is essential that the application does not require many efforts memory, for example.
Finally, so that we can adapt the contents to the maximum number of formats and different contexts, it is advisable to separate the content from the design, using for example the xml format.
However, regarding the term usability we must make an important note and that is that this concept is currently used in such a generic way that it runs the risk of losing its meaning. Sometimes we will hear usability to refer to user study methodologies, other times we will find it referring to the discipline that studies the use of applications and the interactions between them and people and it is even very common to talk about usability in reference to applications whose design has not been taken into account to users: simply the fact that the designer has cared to try, following only your own criteria, the application being easy to use makes it talk about the usability of the application. However, usability is not a discipline, nor a methodology, nor should it ever be based on the opinion of one person (no matter how expert on the subject). In summary, what we must remember is that the concept Usability refers to the ease of use of an interactive system and to We must always base this on the information obtained in studies with users (information that we can obtain with our own studies or through information about studies that others have carried out for similar applications).
1.3.What is perspective user-centered design?
First of all, we must keep in mind that centered design in the user (DCU (3) ) is not more than a perspective, that is, a certain point of view or place from which to look at and understand things. Well, what does this point of view tell us about?
The argument that supports the perspective of centered design the user is they are People are the ones who should focus our attention when we think develop a certain technological application. After all, they are people normal and ordinary people, and not the technologists, who are going to use the applications, those who will be satisfied or not with them and who will ultimately determine success in its implementation.
That is, instead of starting by thinking about the application and try later with some users a prototype that we have created, we should start by thinking on the people who are going to use it: who are they? What do they do? How do they do it? what do they use to carry out what they do? Where do they do it and under what circumstances spatiotemporal? And even, what history does the activity they are carrying out have? out? (Bertelsen and Bodker, 2003; Gutwin and Greenberg, 2002). We should not underestimate the importance of any of these questions, since their answers will give us all of them relevant and significant information in order to think about the solution most optimal for the task that users will carry out.
However, how to get the right answers to these questions? Well then, The user-centered design perspective does not give us the answers, since It is not associated, at the moment, with any precise methodology. More than looking for a method associated with this perspective, what we must do is make use of the different methodologies that exist in the social and human sciences to study users, but putting special emphasis on their tasks and the different interactions that carry out to carry them out: interactions with other people or with different artifacts, some based on new information and communication technologies (such as the Internet or the mobile phone) and others based on previous technologies (such as an analog telephone or a post it).
Indeed, the DCU puts the person at the center of the development. It is a process focused on the different processes that the person carries out while interacts with artifacts and people to carry out a certain task. However, We will find that there are those who differentiate between design focused on use and design centered on the user, understanding the latter as a way of involving opinions of the user in the creation and design process which, as we have already commented, is what which is also known as participatory design (Floría, 2003). But the interaction human-computer is a scientific discipline, which observes users using methodologies that come from the human sciences and that have extensive tradition and justification within them; From these observations, information is obtained about the use and this information is what is applied in the design of the interactive system. From this perspective, user opinions have no place, since Experts in user studies know that users can ask for things that technologically impossible and above all ask for things that later when it comes to The truth is they wouldn't use it!
For this reason, our objective is not to collect information about what the user says but about what it does, although in most cases what it tells us (applying adequately the techniques of testing, interview and focus group) will be very relevant information about their daily practices and expectations. Furthermore, rather than taking into account the verbalization of your wishes, it is much more advisable collect data about your frustrations when developing a task in order to manage to propose solutions in the design that make the development of the task not only effective but emotionally satisfying (Patau, 2000). Therefore, since a scientific perspective, when we talk about a human-centered design perspective user we are not necessarily referring to participatory design; Furthermore, and consequently with what we have argued, its distinction with design-centered In use it becomes unnecessary.
Above all, the conclusion we must reach about the design-centered perspective on the user is that this must be taken into account from the beginning: carry out testing with users during the process or at the end, in application evaluations, obviously it will always be positive, but in this way we will be limiting ourselves to "cover patches." If we want an application to be effective and satisfactory, and that has a really intuitive and easy-to-learn user interface, the user It must be at the center of attention from the beginning. Next we will see How can we incorporate the users' point of view in all phases of design user-centered with the goal of improving the user interface and therefore therefore, the usability of the application.
1.4.The ultimate goal of user study: interface design
Indeed, the objective of studying users is to obtain information that It helps us to improve the existing communication between the user and the application, that is, what is known as user interface.
If we take into account that the interface is the surface of communication between people and technologies, we must realize how our daily lives are full of interfaces. And these interfaces can go from the doorknob to the control panel of a car, so in human-computer interaction we focus in studying those that put us in relation to new information technologies and communication.
We should not understand the interface only as the point of contact and relationship between the person and the technology; Beyond this approach, we must understand that everything that we do not manage to transmit through it will be found completely outside of this relationship (Lorés, Granollers and Lana, 2002). If a certain functionality is difficult to locate in the interface – either due to difficulties in viewing or in interpretation – the user will not use it and the functionality will be nullified in practice. Therefore we must prevent the interface from becoming a barrier due to inadequate design and ensuring that technology is not an element of frustration but rather a facilitating element of the task to be carried out.
Another important element when thinking about the interface of user is that, of the same way that in our daily lives we make use of multiple physical interfaces of more rudimentary technologies than digital technologies, interactive systems They also have multiple devices and formats in which to present information. that go far beyond the metaphor of the desktop on the PC. Take into account this Diversity is essential, since we must take into account all the possibilities What interactive systems offer us if we want applications to go inextricably linked to innovation and success.