In my experience the designs with the best outcomes are based on a foundation of carefully articulated audience personas and scenarios. However, I have witnessed exceptional design outcomes for cases where agility, expert knowledge and intuition have driven results without strenuous research and it’s findings.
Deep understanding of the context surrounding a problem is imperative to produce a successful solution. It’s this knowledge that empowers us to know which details are most important in order to distill the solution to it’s most essential elements. Often the most challenging aspiration of a design may be achieving simplicity as it is tempting to introduce superfluous elements with the objective of creating added value or robustness.