SPRING Reasoning Flashcards
what is deductive reasoning
conclusion that necessarily follows given that the statements are assumed to be true
logic as normative theory
what is inductive reasoning
generalised conclusions that goes beyond the informatino provided
ie scientific reasoning and theories
what are conditionals
deductive reasoning forms
if….then…
if the condition and premise are assumed to be true then the conclusion is logically also true
what are syllogisms
a form of reasoning in which a conclusion is drawn from two given or assumed propositions (premises); a common or middle term is present in the two premises but not in the conclusion, which may be invalid
“some..all..that…are..”
what are relational inferences
making inferences about the relationship between things
ie a>b b>c so a>c
why do we make deductive inferences? (johnson laird and byrne 1991
form plans eval actions interpret and formuate rules/principles pursue arguements weigh evidence compare theories solve problems
what four deductive inferences can be made
valid: modus ponens and modus tollens
invalic: affirmation of the consequence and denial of the antecedent
what is the atecedent
if….. part of the reasoning format
what is the consequent
then…
describe modus ponens
method of affirming the antecedent
logically the consequent follows
90-100% correct
“bob is poisoned”
describe modus tollens
denial of the consequent
logically the antecedent would be false
60% correct
“bob does not die”
describe affirmation of the consequent
logically invalid - should the consequent be true then nothing will follow as may be many causes
40-50%
“bob dies” - any cause
describe denial of the antecedent
logically invalid - should the antecedent be denied, not logically valid to assume the consequent would not still occur - many different factors that also lead to the consequent so stil occur
40-50% correct
“bob is not poisoned” - still die of other causes
what are biconditional arguements
if and only if
following these, all four inferences would be valid
mental models theory (johnson laird and byrne)
when we reason we think about different possibilities - construct based on our understanding of the premise and general knowledge of the world - what is possible, probable and necessary
develop initial model, generate conclsion and look for counter examples to check for validity
BUT dont initially think about all possibilities - MP explicit but MT, DA AND AC implicit and tend to use heuristics
therefore get wrong as dont think further