This is usually easier said than done as most decisions are made within limitations of time and information, increasing the likelihood of most decision-makers relying on assumptions and heuristics. Hammond, Keeny and Raiffa (1998) in their work The Hidden Traps in Decision-making acknowledge that although heuristics generally serve to facilitate mental functioning, there are usually a number of flaws in the way minds work when making decisions.
Values and Beliefs
Personal values and beliefs tend to be forged over time and may reflect the cumulative values and beliefs of one's parents, teachers, community, etc. They are powerful influences on decision-making and are directly tied to how individuals perceive situations, other people, and actions. People will tend to reject and distrust data or solutions that seem in conflict with their belief and value systems, while embracing those that do. Of course, the danger is that simply because information runs contrary to a belief, this does not make the information invalid, and vice-versa. A decision-maker may also tend to believe that his or her personal value and belief systems are universal when they may not be.
