Results from a heuristic evaluation consist of a list of usability problems with references to those usability principles that were violated by the design. Evaluators should try and be specific and should list each usability problem separately. There are two main reasons to note each problem separately [13]:
Studies [11] have shown that heuristic evaluations tend to find more minor problems than major. However, the probability of finding major problems is greater than finding minor ones.
It could be expected that usability problems violating certain heuristics would be easier to find than others. Nielsen [11] shows the effectiveness of finding usability problems using the 9 of the general heuristics (excluding "help and documentation"). It was discovered that user interface problems identified during a heuristic evaluation performed by three evaluators will have about the same probability of being found for most of the heuristics. However, problems that violated the "Prevent errors" and "Clearly marked exits" heuristics were seemingly more difficult to identify. It was recommended that additional measures should be taken to find problems relating to these heuristics.
In another study, Nielsen [14] determined that the majority of usability problems identified in a system were not due to a few factors. There was a gradual decline in the number of usability problems that violated each heuristic. In other words, usability problems were due to a broad variety of heuristics being violated.
Nielsen [11] also looked at whether the circumstances under which the problems could be located had any influence. He stated that usability problems can be located in four different ways:
It was found that evaluators were just as good at finding usability problems no matter what kind it was.