What is human-computer interaction (HCI), and which disciplines contribute to it?

Human-computer interaction is the study and design of how people interact with computers, apps, websites, and more recently, AI tools. HCI is a multidisciplinary field which acts as a combination of computer science, psychology, sociology, linguistics, and Artificial Intelligence.

What is the difference between a system being useful and being usable? Can you give an example of a system that is usable but not useful for a particular person or task?

A system is termed usable when it is easy and intuitive to use, and does not cost a person effort and time. On the other hand, a system is considered useful when it serves a meaningful purpose and solves a concrete problem. An example of a feature which is usable but not useful would be the dedicated Calculator button on keyboards; while extremely accessible, it does not solve an existing challenge and merely makes a rarely used function easy to execute.

Find an everyday interface that is confusing to use. What is the person trying to do, and which design decision causes difficulty? Suggest one improvement.

I believe the design of the Terms and Conditions pages of many websites and applications is a pretty confusing one to navigate. While essential to the creation of accounts within these systems, the overall look of the T&C page resembles that of something irrelevant, and this is a direct antecedent to why most users completely ignore reading these sections. The cramped nature of the text, the lack of clear headings, and the monochrome colour choices contribute to the listless visual design of these pages. I think that the creator of these designs is attempting to rush over the formalities, since most people would not care about the T&C even if they read it. However, I would still modify the overview of these pages in such a way that the user is at the very least able to grasp the central terms they're agreeing to.

What is a prototype, and how can testing one with users help a designer? What is one thing that asking “Do you like it?” would not tell you?

A prototype is an early model of a product or system that is primarily used as a testing interface rather than a fully functioning program. Testing prototypes with users can immensely benefit designers, since this can aid in improving usability and utility. Through recording responses about the ease with which users were able to navigate through the prototype, one could catch usability issues before the final coding or manufacturing process begins. However, what such "do you like it?" questions do not address is the overall utility for the broader target audience, and only through analyzing utility via deeper questions such as "how did this help you?" or "what problem does this solve?" can we contemplate on the functionality of the prototype and not just the design.

Find one example of interaction beyond a keyboard and mouse, such as voice input or a tangible interface. Who might benefit, and how would you test whether it helps them?

An example of such an interaction would be the design of TV remotes. Since TVs play a central role as means of relaxation at home for many people, an efficient design of the remote could help bolster both functionality and ease of access. This could be checked by testing sample design formats for buttons on the remote, and evaluating which buttons and features are used most frequently. Additionally, a subjective survey would also be helpful in analyzing how easily users can access their priority functions within the TV.

Learn more about the connection between humans and our technologies through these links below!

Usability versus Usefulness: how they aren't the same yet are equally essential
What prototypes are and why they're pivotal to design development
A beginner's guide to human-computer interaction