Human Computer Interaction is like a bridge between human users and computers. It is related with design, evaluation and implementation. HCI is used to make the process more efficient and safe. It provides an alternative way to make the design time less through various other task models. The disciplines contributing towards it include:
Useful: A system is deemed useful when it actually solves a real-world problem. A system does what it should — "Fit for purpose."
Usable: It is called usable when it is easy, efficient and comfortable for a person to use and operate on. A system feels easy to do that said task — "Fit to be used."
Example: A tip-calculating app on a phone during a solo fast-food trip. This is usable as it has large buttons, a clear interface and user-friendly animations. It is not useful because fast-food joints do not require tipping and there is no bill to split.
A hotel shower valve serves as the perfect example.
What the person is trying to do: The user wants to adjust the shower temperature according to their likes and dislikes.
Confusing design: Most modern designs use a single knob that requires the user to pull out to turn on water and then rotate to change the temperature. Lack of any visual aids or directions can cause the user to be confused between the pull and rotate options. Hidden controls for changing the style of the shower spray can cause further frustration and irritation. Delayed feedback is the ultimate fuel to the fire for the user — when the water takes more than the required time to change temperature, the user can get irritated.
Improvement: Visual control guides, or a double control lever system, which clearly specifies and guides the user on how to accurately operate it.
A prototype is like a trial and error model. It is an earlier, experimental model used to test the concepts and gather feedback before investing time, money and effort into the final product.
Uses:
The "Do you like it?" question doesn't specify whether the user will actually use the system to complete the said task.
A voice-controlled smart home lighting system is an excellent example of interaction. People with mobility impairments or visual impairments would benefit greatly from this system.
To evaluate the voice control, we can conduct usability tests comparing the new voice interface against the previous ones. We can also conduct test setups and tasks by giving small tasks using our voice to test it, then check for any scope of error and rectify it.