The following was adapted from “Hueristic Traps in Recreational Avalanche Accidents: Evidence and Implications” by Ian McCammon (2004). Below is simply a summary, the real article is just 9 pages and written in a style for the general public.
Human factors are decision making patterns that lead to increased risk taking and increase probability of accidents. It appears that when certain psychological cues are present, people find it difficult to heed more objective cues about avalanche hazard. These psychological cues have very little to do with conditions and a lot to do with our unconscious assumptions, biases, and habits.
FACETS is an acronym listing the human factors described below. In the FACETS test, you simply run through the list and see which cues are present. Depending on your experience, group size, etc, each cue may have a different level of influence on your objectivity. But in general, the more cues that are present, the more difficult it will be for you to objectively assess the danger.
“Parties traveling in familiar terrain made riskier decisions than parties traveling in unfamiliar terrain. This effect was especially pronounced for parties with substantial experience and training.”
Group members want to be accepted by members of their parties. “Accident parties that included females made riskier decisions than parties of all males. The effect was most pronounced in parties with little avalanche training. It is notable that these were precisely the parties in which women were least likely to participate.”
Parties that were highly committed to a goal – a summit, ski slope or an objective in deteriorating weather – made riskier decisions than parties just out for a day. This effect was most pronounced in parties of four or more.
Accident parties often contained a de facto leader – someone who was more experienced, older, or more skilled. Novices were were more likely to follow the leader into dangerous situations than when novice groups made decisions by consensus.
Parties took more risks when they were racing a closing window of opportunity, such as competing with another group for first tracks.
When skilled parties met other people in the backcountry, they were more likely to take risks than parties that were less skilled. This effect was most pronounced in groups with the highest levels of training.