Introduction to IHC - Human Computer Interaction

Get to know the area that studies the interaction between people and computer systems

Welcome to)!

What would be the best way for software to have real success in a competitive market, receive good feedback, be recommended and attract more consumers?

Regardless of the marketing strategy that will be adopted, I believe that the first concern is to offer a product with a user-friendly interface, that is, easy to use and with the possibility of intuitively interacting with the basic functionalities.

A product with these characteristics enables experiences that positively impact people's lives.

In this article I present the area of IHC - Human Computer Interaction. This area focuses on the human side of interaction with computer systems that promote positive experiences for the public and consequently contribute to the product's success.

Prepared? so come with me!

In this article you will learn about:

"Inside-out" and "Outside-in" approaches

In order to understand what the HCI area intends to emphasize, we need to know two approaches to the development of interaction systems. These are the “Inside out” and “Outside in” approaches.

A problem arises when interactive systems are built with a focus only on the physical aspects of the building. We can call this approach “Inside Out”.

"Inside-out" approach to developing interaction systems
"Inside-out" interaction systems development approach

These systems are developed with greater concern for the quality of construction, construction process, cost, durability and other issues that take little account of the quality of use by the user.

  • This approach is characterized by:
  • Disdain for the interface;
  • Greater focus on the system;
  • Inconsiderate software design;
  • Inadequate development process;
  • User-system interaction not evaluated.

This increased focus on the “inside” causes damage to the user experience because it results in inappropriate interactive systems.

Fortunately, there is an increasing number of developers, designers and development companies concerned with the improvement and quality of the use of the designed interfaces.

Approach to developing "outside-in" interaction systems - Human Computer Interaction
"Outside-in" interaction systems development approach

By focusing on this improvement, they use the “From Outside to Inside” approach, an approach that ensures greater competitiveness in the market.

What is HCI (Human Computer Interaction)?

A IHC area works with an “outside-in” approach. I will use Hewett's definition here to explain what IHC is.

"Human-Computer Interaction (HCI) is a discipline focused on the design, evaluation and implementation of interactive computer systems for human use and the study of important phenomena that surround them." (Hewett et al., 1992).

It was in the mid-1980s that IHC was widespread as an area of study. This is due to the historic Gaithersburg conference in 1982 “Human Factors in Computer Systems” (translating; “Human Factors in Computer Systems”). Since then, the IHC has become an international activity with industrial impact all over the world.

As the IHC area is involved with the study of phenomena that occur in the interaction of human beings with computer systems, it is extremely important to know the elements involved in the interaction process.

Elements involved in the interaction process

Next, I will show concepts that allow us to identify the elements involved in user-system interaction. Being the first concept of Context of use it already demonstrates very well about the function of each of these elements.

Context of use

The Usage Context is characterized by every situation relevant to interaction with the system. It is included in the context, when the system is used and where the interaction takes place (the physical, social and cultural environment).

The figure above illustrates a user in a given context of use, seeking to achieve a goal, when interacting with the interface of an interactive system.

No momento que eu, Ed Francisco (USUÁRIO), em meu escritório (CONTEXTO DE USO),  edito este artigo, me vejo em um PROCESSO DE INTERAÇÃO, onde eu digito e formarto o texto, e insiro imagens usando o Gerenciador de Conteúdo WordPress (SISTEMA) para que ele seja publicado no blog do Chief of Design (OBJETIVO).


the possibility of interaction it happens when a system provides an interface for the user to act.

human computer interaction

According to the definition of Hix and Hartson (1993): “In general, the user-system interaction can be considered as everything that happens when a person and a computer system unite to perform tasks, aiming at a goal”.


A interface it is the contact between the user and the system. It is the portion of the system that maintains contact during the interaction. The hardware and software used during the interaction makes physical contact at the interface possible.

Interface - Human Computer Interaction
The keyboard allows physical contact on the interface.

The user can actively interact with the system through input devices such as keyboards, mouse and webcam. While output devices such as speakers and printers transmit system reactions that the user receives passively.


A button drawn on the graphical interface of a system suggests to the observer the possibility of pressing (a type of use) to reach a goal. So he uses the mouse for that.

Therefore Affordance it refers to the characteristics of physical objects that allow us to identify their functionalities through their attributes.

IHC objectives

The objectives of IHC are characterized in how to define methods to design reliable, useful, user-friendly interactive computer systems that take into account cultural, cognitive, emotional, and intellectual factors of the target audience.

These goals are in line with the concept of Systems Acceptability proposed by the renowned Web Usability Consultant, Jakob Nielsen.

Systems Acceptability

The acceptability of a system is divided into social acceptability and practical acceptability.

Social acceptability is about acceptance of the system. There it is verified whether the users believe that the system can improve the progress of their activities without hindrance.

Practical acceptability concerns parameters such as cost, compatibility and reliability, etc., and also a category called “usefulness”.

In the category “Usefulness” it is verified whether a system can be used to achieve a certain objective. You work there with attributes of utility and usability.

About the Utility, it is verified if the system does what must be done according to the proposed objective. Usability is related to how well users can use a system tool in order to perform a specific task.

Benefits of human computer interaction

The study and practice of HCI should be encouraged because they can provide direct benefits to the user and also to society in general.

Benefits for users:

  • Increased user productivity;
  • Reduction in the number of errors;
  • Reduced error severity.

Benefits for companies:

  • Competitive advantage;
  • Increased sales.
  • Training cost reduction;
  • Cost reduction with technical support;
  • Cost reduction with development;

Areas related to the IHC

Logically, since the IHC is an area whose final result of its actions is the user's well-being, it would involve other areas of human knowledge.

The complexity of analyzing user-related factors such as health, comfort, safety, and behavioral characteristics, with the user interface, with the system's functionalities, with the tasks to be performed, with restrictions and with productivity issues, justifies the use of technical knowledge from various areas.

Therefore, the IHC benefits not only from computing, but also from knowledge and methods from other areas, which makes it multidisciplinary. Much of this technical knowledge is imported to be tailored to your needs.

Among the areas that contribute to studies of interaction phenomena are:

  • information systems;
  • computer sciences;
  • engineering;
  • psychology;
  • sociology;
  • anthropology;
  • philosophy;
  • graphic design ;
  • ergonomics;
  • artificial intelligence.

Final considerations on Human Computer Interaction

The interaction with systems is something more than common nowadays in people's routine. So there can't be room for products that don't provide a good interactive experience and that don't care about the behavior and feelings of these users.

A serious professional should take these aspects into account when designing their system interfaces. And knowledge about HCI can supply you with the best guidelines.

Fortunately, the HCI area counts on the contribution of professionals from different areas who, with added efforts, build the best paths for the development of the most adequate interaction systems for users. Whether they are professionals who master technology and are able to develop systems, or professionals who study about man, about society and are able to provide information about human capacity.

Então é isso! Se você gostou desse artigo deixe o seu like e compartilhe com seus amigos que tiverem interesse no assunto.?

Take the opportunity and leave your opinion, doubt and/or experience in the HCI area, in the comments below.


Ed Francisco

Olá! Aqui é Ed Francisco, colaborador do Chief of Design desde suas primeiras linhas de conteúdo e de códigos.

Speaking of code, I believe HTML is the most remarkable web technology that has allowed me to get to where I am, and also write these lines about me for you.

I have a degree in Production Technology (this is where I got to know HTML) and a Technician in Digital Production, Web and Multimedia (where I improved my knowledge of HTML).

I'm from São Paulo from the East Zone. I ventured trying to unravel the mysteries of the web since 2008.