reason and decision making Flashcards
what is reasoning?
- the action of thinking something in a logical or rational way to make a decision
- use our existing knowledge to draw conclusions, make predictions ,or construct explanations
inductive reasoning
- make broad generalisations from specific observations until something forms an exception
- if i drop this pen everything will drop to the floor
- numerous experiments show reinforcement is required for learning, it is essential
- hypothesis might not be true, as can’t be sure all future experiments will show same results
deductive reasoning
- reaching a specific, logical conclusion from general statements or hypotheses
- typically structure as folllows:
1. first premise (or statement)-p1, all cats meow
2. second premise-p2, rover is not a cat
3. inference (or conclusion), rover does not meow - related to problem solving, goal to solve reasoning task but solution isn’t always obvious
- assume premise are always true (or valid)
- conclusion can either valid or invalid
conditional reasoning
premises
- if i go out side (antecendent) , then i get wet (consequent)
conclusion
- therefore i have gone outside
modus ponens
premises
- if the weather is nice, david takes a walk
- the weather is nice
conclusion - therefore, david takes a walk
modus tollens (denying the consequent)
premises
- if the weather is nice,david takes a walk
- david does not take a walk
conclusion
- the weather is not nice
conclusion VALID for both problems
- however, typically perform better for modus ponens. e.g. correctly argue that the conclusion is valid
affirmation of the consequent
premises
- if you mow the lawn (antcedent)
- i will give you a pound (consequent)
- i give you a pound (affirmation of consequence)
conclusion
- therefore, you mowed the lawn
- invalid conclusion
denial of antecedent
premises
- if you mow the lawn
- i will give you a pound
- you do not mow the lawn
conclusion
- therefore,i don’t give you a pound
syllogistic
- consists of two premises followed by a conclusion that is either valid or invalid
- contains 3 items
- premises and conclusions contain quantifiers e.g all, some
reasoning
- validity of conclusion depends only on whether it follows logically
- validity in real world is irrelevant
- belief bias causes erros in syllogistic reasoning
- accept invalid conclusions if they are believable
- reject valid conclusions if they are unbelievable
belief bias
conclusions for both problems are valid (they follow logically from the premises, although we know that the second example cannot be valid in the real world
mental model
- since our working memory is limited our mental models are as simple as we can make them
- inferences based on one mental model will be easier than ones requiring multiple models
- we stop searching when we have a valid believable conclusion
- knowledge can influence the process of inference
- mental model constructed alternative models to falsify conclusions
- reasoning problem may require several mental models that are harder to solve
mental model- limitations
does not describe how we decide which info to include
mental model example
premises - lamp is on the right of the pad
- the book is on the left of the pad
- clock is in front of the book
- pen is in front of the lamp
conclusion - clock is to the left of the pen
dual system theories
- no direct evidence that there are separate heuristic and and analytical processes
- does not explaion how heuristic and analytical processing is conscious
- but can sometimes be unconscious
informal reasoning
- refers to the process of everyday reasoning, contrasts with artificial, logic reasoning tasks
- unlike logic reasoning, informal reasoning:
- is based on knowledge and experience
- has little to do with formal logic
importance of informal reasoning
– Content = plausibility
– Context = expert vs. non-expert
– Probabilities = possibly/probably true – Motivation = support our viewpoint
