You can never truly imagine all the ways a user interacts with your product. This is due to what we call the empathy gap: it’s a bias where we aren’t fully able to predict someone’s feelings, thoughts and behaviours. So how do you fix this?
First, understand why this exists: we stand too close to the product, knowing its assumptions. Users have different contexts, levels of expertise or expectations that are not necessarily aligned with your team.
Next, look at what stage you’re in the product development cycle and attempt to close the empathy gap:
Are you in the early stages? Use circumstantial research such as interviews, diary studies, …
Are you in the late stages? Shift to validation research: think of usability testing, tree testing, heuristic evaluation, …
Are you post-launch? Continuously observe real-world usage with tools like Smartlook to surprise yourself in the behavioural patterns.
You can never close the gap 100%, but you can avoid mistakes that in hindsight are obvlious.