- Two types of reasoning:
- Deductive reasoning – reasoning from a general principle to a specific case
- Basis of formal mathematics and logic
- Viewed as stronger and more valid reasoning because conclusion cannot be false if premises are true
- Syllogism: If all humans are mortal (first premise), and Socrates is a human (second premise), then Socrates must be mortal (conclusion)
- Inductive reasoning – reasoning from specific facts to develop a general principle
- Leads to likelihood rather than certainty
- New observations may disprove conclusion
- Deductive reasoning – reasoning from a general principle to a specific case
- Stumbling Blocks in Reasoning
- Distraction by irrelevant information – people take into account irrelevant information that leads them astray
- Failure to apply deductive rules – people think of problem solving methods as to be used only in certain situations and cannot apply to new problems
- Belief bias – tendency to abandon logical rules in favour of personal beliefs
- Students claimed conclusion was not correct to following syllogism: All things that are smoked are good for one’s health, cigarettes are smoked, therefore cigarettes are good for one’s health
Problem Solving
- Four stages of problem solving:
- Understanding, or framing, the problem – problem must be framed optimally to have chance of generating an effective solution
- Generating potential solutions – must determine which procedures and explanations will be considered, and which solutions are consistent with evidencb
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- or procedures that automatically generate correct solutions
- Heuristics – general problem solving strategies that are applied to certain classes of situations
- Means end analysis – identify differences between present situation and one’s desired state/goal and make changes to reduce differences
- Subgoal analysis – people can attack a large problem by formulating subgoals or intermediate steps toward a solution
- Uncertainty, heuristics, and decision making
- Representativeness heuristic – rule of thumb in estimating probability that an object or event belongs to a certain category based on extent to which it represents a prototype of the category
- Tversky and Kahneman note that people confused representativeness with probability
- Availability heuristic – rule of thumb used to make likelihood judgments based on how easily examples of that category of events come to mind or are available in memory
- Example: people were less likely to book flights following September 11th, since the memory of the event is readily accessible
- Representativeness heuristic – rule of thumb in estimating probability that an object or event belongs to a certain category based on extent to which it represents a prototype of the category
- Confirmation bias – people tend to look for evidence that will confirm what they currently believe rather than look for evidence that could disconfirm their beliefs
- Sternberg and Davidson found that correct solutions to insight problems involve:
- Selective encoding – choosing what information matters
- Selective combination – choosing what’s important within chosen information
- Selective comparison – out of chosen information, how does it apply to the problem
