The Gulfs of Evaluation and Execution (Norman, 1986) describe the gaps users face. Evaluation happens when a user interprets feedback to understand the product's current state. A clear path of execution is needed for a user to reach their goal. If either is unclear, the user will not know what to do, may repeat actions, or feel anxious that their task did not complete.
Intuitiveness in BASIC UX is about how learnable a product is. Very few things are innately intuitive. Using a pencil seems intuitive but is actually learned. The point is that a product can be learned and that users should not need to relearn it over and over. That learning should be as small an obstacle as possible. Affordance matters too: the color of links or the shape of buttons cue the user about what elements do. Most people spend most of their time in other products, so building on established patterns is key.
Questions to ask
- Is the functionality clear?
- Can the user reach their goal with little or no instruction?
- Can the task be repeated without further instruction?
- Can the user predict the outcome?