The role of usability evaluation as it relates to Human-computer interaction cannot be underestimated.The Software development process consists of an interconnected set of essential ingredients such as the analysis, requirement specification, design, implementation, testing, and maintenance phases. Interestingly, usability evaluation play a vital role in software testing. However, when it has to do with Human-computer interaction, the interaction between users of the software being tested and the functionalities of the software's Graphical user interface will help provide meaningful feedback that can be instrumental at improving the overall quality of such software.

The role of usability evaluation as it relates to Human-computer interaction cannot be underestimated.The Software development process consists of an interconnected set of essential ingredients such as the analysis, requirement specification, design, implementation, testing, and maintenance phases. Interestingly, usability evaluation play a vital role in software testing. However, when it has to do with Human-computer interaction, the interaction between users of the software being tested and the functionalities of the software's Graphical user interface will help provide meaningful feedback that can be instrumental at improving the overall quality of such software.

The role of usability evaluation is like a role played by a supporting actor/actress in a movie ... We tend to answer the following question: "who is it for..."

Usability evaluation does not limit itself to 'performance' evaluation. When we perform usability testing, we ask users/participants to complete a task whilst providing them with a blueprint of how the software system works. Now a user has a goal and starts a Norman action cycle to achieve that goal. Thus during usability evaluation we can find out if it is INTUITIVE for a software feature to be used under a given problem scenario.

These are all interesting perspectives, but usability is only one of the relevant characteristics to evaluate an interactive software or device. More importantly is, for example, to understand if the specific artifact is addressing the right problem, if it integrates with people's lives, and how it influences the perspective of its users...

I would say it answers the question of whether (or how well) the system will actually help people achieve their goals. If you look at the definition, usability is about (specific) users achieving their goals (in a given context).

As a final comment: can you think of usability evaluation unrelated to human-computer interaction?

The usability concerns essentially to ask about the system ease of use and learnability. Then, it is important to assess a system usability.

The role of Usability Evaluation is very important when software testing phase starts. The software development process is completely dependent on the Need. Based on the need of a person or a group or a community developers develop a solution which can be used and accepted by the end-user and while doing so if the end-user gives feedback the end result will be the software product will be of good quality. This is possible only when end-user uses the software product and if at all the product is difficult to use then the feedback provided by the user will only be related to usability and rest of the attributes will not be tested properly. Once the usability is okay then only the end-user will try to explore further and give appropriate feedback for the improvement of the software product. Therefore, it can be said that Usability Testing is just like an entrance for the testing of a software. If the entrance is tested properly and a software engineer succeeds in that then the probability of having a quality software increases.

Refer the following article

https://globaljournals.org/GJCST_Volume15/3-Usability-Evaluation-of-Learning.pdf