Week 8 Lecture 7 - reasoning Flashcards
What is inductive reasoning
Start with a premise and arrive at a conclusion
What is deductive reasoning?
Given a premise is true you can move towards a true conclusion (strict logic)
What are the 2 kinds of deductive reasoning?
- syllogisms
- propositional reasoning
What do syllogisms typically comprise of?
two premises and a conclusion, and involve the quantifiers all, no, some, and some…not
What do you conclude with a syllogism?
given relationship between A and B AND B and C
can conclude something about A and C
How might heuristics explain people’s difficulties with syllogisms?
Atmosphere theory
- the mood of the premises influences judgments about what the mood of the conclusion should be
- “Mood” means whether the statement is affirmative or negative, and whether it is universal or particular
- E.g., “all…” is universal and affirmative, whereas “some are not…” is particular and negative
What evidence is there for heuristics explaining syllogisms?
- ppts matched mood of premise to mood of conclusion even though there was no correct answer
- provides evidence for atmosphere theory
- however, doesn’t explain why people sometimes correctly infer “no valid
conclusion”
How might comprehension explain syllogism difficulties?
“Errors” in syllogistic reasoning partly reflect differences between the use of language in formal logic and in everyday life.
What evidence is there for comprehension as an explanation of syllogism difficulties?
Clarifying premises greatly reduces the “error” rates
(Ceraso & Provitera, 1971)
How mental models might explain difficulties in understanding syllogisms.
What are the steps involved in this approach?
- Step 1 Construct a mental model of world implied by premises
- Step 2 Make a composite model and draw a conclusion
- Step 3 Validate by searching for alternative models and checking they don’t contradict the conclusion
What are the 2 types of mental models?
single and multiple
In multiple mental models, the more alternative models are considered, the more likely one is to draw the correct conclusion (example of a research premise)
What does this require more of though?
time, effort, mental capacity
What did evidence about multiple mental models for syllogisms find?
- More possible models = less accurate + slower
- Higher working memory = faster and more accurate
- But not direct evidence for model construction/validation
What did a study directly testing the generation of alternative models in mental models of syllogisms find?
“reasoners are able to construct alternative models…but [they] normally construct only one”
How might framing and experience explain difficulties in understanding syllogisms?
Syllogistic reasoning is affected by the framing of the problem and the participant’s prior experiences.
What did a study into framing and experience and syllogisms find?
- plausibility increased the judged validity of both valid and invalid arguments
- judgments about argument validity are influenced by beliefs both about the conclusions themselves and about the probability that those conclusions will be true.
What is the dual process framework of reasoning?
- People only construct one model
- If the conclusion is believable: look for consistent model
- If the conclusion is unbelievable: look for inconsistent model
- If desired model can’t be constructed then swayed by belief
- Belief produces overall bias AND affects reasoning itself
What is propositional reasoning?
Propositional reasoning involves reasoning about propositions containing the conditionals: If, And, Not, and Or.
How might heuristics explain difficulties with propositional reasoning?
confirmation bias –> confirmatory testing
What did a study into heuristics and propositional reasoning find?
simply choosing items that are explicitly mentioned in the problem statement – a “matching heuristic” – might be one simplifying strategy when faced with this kind of task.
How might comprehension explain difficulties with propositional reasoning?
propositional reasoning “errors” may often reflect the participant’s interpretation of the terms.
What did a study into propositional reasoning and comprehension find?
Many people misunderstand the rule, but reason consistently after that
(Gebauer & Laming, 1997; Wagner-Egger, 2007)
How might mental models explain difficulties with propositional reasoning?
can be applied to propositional reasoning in the same way that it can be applied to syllogisms
How might framing and experience explain difficulties with propositional reasoning?
framing and experience shape people’s responses in propositional reasoning tasks, and these effects illuminate the underlying mental processes.
