Seismic data play a prominent part in the quantification of the subsurface. Improved imaging and calibration give us a better starting point for interpretation and uncertainty analysis. However, aside from the technical aspects of evaluating seismic data, there are human factors that play a role in the way we use and analyze the data, and these tend to work against attempts to quantify realistic uncertainty ranges. We used a case study to reveal some common pitfalls and assumptions that can compromise our ability to produce sufficiently wide uncertainty ranges in our evaluations. The example highlighted three human factors that affected the decision-making process: anchoring, availability, and overconfidence. Interpreters should avoid anchoring on a base case and focus on alternative possibilities. They should be wary of judging which methodology is best only by the ease with which it comes to mind. Technical specialists should guard against overconfidence in their data, interpretation, and ability to describe the full uncertainty space. We suggested alternative methods that allow us to restore that uncertainty range using a multideterministic approach incorporating multiple data sets, interpretations, and methodologies.