HCI and Software Engineering basics

Let's start answering these question: What does HCI stand? What's Interaction Design about?

HCI stands for "Human Computer Interaction", the HCI discipline is concerned with the design of computer systems that help people to perform their activities productively and safely [1].
Interaction Design is about designing interactive products to support the way people communicate and interact in their everyday and working lives. This approach considers user experience (UX) [1]. To learn more about user experience, check out Usability.gov the leading resource site for UX best practices and guidelines, from this site I strongly recommend starting with Interaction Design Basics.

HCI and Interaction Design are multidisciplinary, within the wide range of disciplines we will focus on Software Engineering. In the Software Engineering market, usability is a pending issue, when we talk about usability the term denotes the ease with which people employ a tool in order to achieve a particular goal.

As we can see in the picture above, Garfield is really messed with his computer :-? but Garfield, like everyone, doesn't want a computer friend, he wants to get on with his work, so we must say NOT USABLE instead of "not user friendly" because the user can not accomplish his goal. 

When someone wants to buy a software product, you want quality and quality includes usability (a basic software feature). Thinking about usability, people tend to think about the user interface (UI) of the software product but these two concepts are not synonymous. The UI is just the visible part of the system.

And what about the User Experience?

According to Tom Stewart: we define it as "all aspects of the user's experience when interacting with the product, service, environment or facility" and we point out that "it is a consequence of the presentation, functionality, system performance, interactive behaviour, and assistive capabilities of the interactive system" [2]. This essentially means that UX includes many aspects such as human factors, design, ergonomics, HCI, accessibility, marketing as well as usability. Of course, Apple is particularly good at this field, the group of UX conditions can be sorted by representing them as concentric circles from the most basic to the least, as shown in the diagram below:

Usability is not properly addressed in most developments, on spite of its importance. Take into account usability at the begining of the development process is more profitable since later becomes more expensive and harder to lead.
The way to deal with usability is to assume a User-centred design process in which the design is based upon an explicit understanding of users, tasks and environments; knowing that the system is not isolated, it is surrounded by the context of use.

Focusing on interaction design, design usable software needs the integration of the skills and techniques of the HCI community (it has techniques to develop usable software) and the Software Engineering community (it  has the knowledge about software systems development).

[1] Ferré, X., 2015. Human-computer Interaction basics slides as part of the subject 'Interaction Design'. Msc EMSE, Universidad Politécnica de Madrid.

[2] Stewart, T., 2008. Usability or user experience, what’s the difference? - accessed on March 1, 2015