When we look at usability and UX, it’s easy to get too focused on specific technical things regarding GUI design, procedures, standards and the like, and overlook very important usability human factors that must be considered. See, human beings are unpredictable creatures in many respects, but paradoxically, they also follow some base patterns on average as well.
Since humans aren’t perfect, usability human factors often account for the obfuscation of human perception, as well as flaws in human patience, timing and steadiness of physical interaction.
We see eye tracking talked about a lot in usability, in how to guide the user to notice and make note of the components in a page or on a form in the order we most want. As we guide their seeing elements in an order, we also shape, by this order, how they perceive the overall structure. Without this, users will be lost and overwhelmed by a mess of controls they have no bases to begin using.
Well, that’s one of the human factors, but it’s just an example itself. There are many more, such as the human perception of work being done by a digital construct. Over time, as operating systems and web browsers became more advanced, busy windows could still show signs of life while busy, distinguishing them from being frozen and non responsive.
The human tendency to expect this life in a functioning mechanism has to be accounted for.
This stretches further to accounting for, I guess you could call it twitchiness. This is mainly a touch screen situation, as users could accidentally tap a control repeatedly, unsure they pushed it, etc. Showing life in button pushes, or accounting for too many rapid presses is important.
Order of operations, with a branching structure to where one goes to accomplish a set of tasks is also crucial. Human minds will group different tasks together by various relevant contexts, and laying out your interface and menus with logical branching groups like this to mimic that human mental compartmentalization makes it much more natural in meeting the pace of the users.
Finally, while this is far from the end of the list, another big factor is designing your navigation patterns and layout in a way that the user learns it naturally, versus memorization. Memorization is not the same thing as truly learning a thing, it is merely memorization of steps that accomplish what one should have learned. Only when something comes natural after full grasping, is it truly learned. But, your UI and navigation have to match the needs to make that happen. It’s not easy, but you can do it, not to worry.
These are mere examples of many usability human factors that have to be accounted for, and these give you a good idea of the nature of the types of things this has to cope with. One can see the loss of integrity between humans and devices, and designing the layers of interface and representation to best take input and present comprehensible output is absolutely crucial.
Never let anyone say interface and interaction design were easy or no brainers, because anyone who says that is full of something I shan’t say here.