reasoning Flashcards
Deductive reasoning
drawing conclusions that are logically sound presuming the premises are true - top down reasoning
inductive reasoning
drawing conclusions infering from the present evidence as to what is probable, not certain
(bottom up logic)
two types of reasoning
Inductive and deductive
define reasoning
conditional reasoning
Type of deductive reasoning
what is conditional reasoning
deals specifically in conditional statements “if then” reasoning under conditions that statements are true
conditional reasoning study question
If its raining freds hair gets wet, it is raining. Freds hair is wet?
conditional reasoning study question Fred result
98 % said yes (Marcus and Rips, 1979).
Conditional statements pt,2 W Fred
If its raining freds hair gets wet. Freds hair does not get wet, it is not raining
Conditional results pt,2 W Fred
52% agreed it was not raining (Marcus and Rips, 1979).
Conditional statements pt,3 W Fred
If it is raining, freds hair gets wet. Freds hair gets wet. It is raining.
Conditional results pt,3 W Fred
33% agreed it was a valid statement. (Marcus and Rips, 1979). It was invalid.
Conditional statements pt,4 W Fred
If it is raining, freds hair gets wet. It is not raining. Freds hair does not get wet.
Conditional results pt,4 W Fred
21% said it was valid. I was not. (Marcus and rips 1979)
What Fred shows.
Conditional reasoning can be tricky and misleading due to lack of external factors
Why do we fail? (conditional)
People can reason logically, but fail to understand logical formal tasks. (Braine 1978)
Why do we fail? (conditional)
People do not reason logically (woodworth 1935)
Why do we fail? (conditional)
We should not expect people to reason with formal logic (Oaksford 1994)
THEORIES OF DEDUCTIVE REASONING
-abstract rule theory
- mental models
- dual systems approach.
Abrstract rule theory (who)
Braine 1978
Abstract rule theory (what)
People use abstract generalised rules to guide their reasoning processes. these derive from past experiences
Abstract rule theory
Link
21% - freds hair (see prior flashcards).
Abstract rule theory - reducing comprehension era
Performance can improve with further clarity (reduces comprehension era Braine et al 1984).
Abstract rule theory - comprehension errors.
However such additional information can also impair performance on some tasks (Bryne 1989).
Abstract rule xplains for errors in judgement including
Overgeneralisation Misapplication of rules Confirmation bias
Mental model theory (who)
Johnson-Laird 1999
Mental model theory (what)
Everyday comprehension processes are used on reasoning problems. These are created through mental models
Mental model theory (what) (2)
reasoning involved examination of mental models and attempts to create alternative models.
Mental model pratical objectives
Mental model pratical Results
principle of truth (who)
Johnson-Laird (1999) pg. 116
principle of truth what (1)
Conclusions are drawn based on the initial model. People then try to falsify that conclusion by constructing alternative models.
principle of truth what (2)
The creation of alternative models is very demanding on working memory.
THEREFORE “individuals … tend to construct mental models to represent explicitly only what is true…”
Newstead et al 1999 theory
Mental models theory predicts that people will consider more conclusions in problems where they must create more mental models
Newstead et al 1999 results
gave tasks permitted one or several mental models. No difference in number of conclusions considered
mental models theory explains reasoning eras
cognitive load
sequential reasoning
dual systems approach (who)
Evans (2003)
dual systems approach
reasoning involves two systems
- fast automatic based on prior knowledge
- slow deliberate abstract based off logic
dual systems approach example
condition 1
system one - buying new car
gut feeling
intuitive
appearance based
excited about how it looks and if its stylish
dual systems approach example condition 2
system two
slow deliberate thinking
analysing cars specifications
comparing
long term costs and effects
Wason and Shapiro 1971
Four cards, Manchester, leeds, train, car
rule; every time i go manny Its by train, each card has a location on one side and method of transport on the other. Select the cards you need to turn to decide wether its false.
Wason and Shapiro 1968; 71.
Manny and car; 62%
Wason and Shapiro AD47
Rule; if thers an A on one side of the car then there is a 4 on the other side
Task; each card has a letter and number. Select the cards in order to figure out rule
Wason and Shapiro AD47 results
4% in original version.
Cheng (1986)
40 hours of training does not improve perfromance
Griggs and Cox; Wason and shapiro
Griggs and cox 1982; extremely difficult task even for intelligent subjects
Griggs and cox experiment
4 cards; beer, coke, 22, 16. if a person is drinking beer they must be over 19.
turn cards to determine wether this is true.
Griggs and cox experiment results
73% got it correct (beer and 16)
Deductive reasoning summoning (long flashcard, no stress).
Determining the conclusions that must follow
given that certain statements are true
* People make characteristic errors in
deductive reasoning
* These are attributed to:
– Failure to understand the task
– Lack of logical approach
– Tendency towards probabilistic approach in line
with real-life reasoning
Inductive reasoning
going beyond information provided to generalise conclusions - hypothesis testing.
Inductive reasoning task
group of two - pA choose any three numbers
pB learn a rule and say if its true or false
Inductive reasoning task rule
any 3 ascending numbers
Inductive reasoning task purpose
the pattern is extraordinarily simple yet participants struggle to achieve it as theyre searching for a pattern - pattern reinforced by the name 2-4-6 task.
Inductive reasoning task who?
Wason. 1960
Inductive reasoning task original findings
21% on first statement of rule, 70% by the end.
Wason quote - inductive
‘There is a peculiar sort of helplessness
about this kind of behavior which was
intensely interesting to watch but difficult
to evaluate’
– Wason (1966)
Wason findings evaluation - inductive.
Wasons selection tasks reveals the tendancy to seek confimration and avoid discrimination. Causes overconfidence in judgements and resistance to change
Eval on Wason - external study
Perfromance does not improve when instructed to use a disconfirmatory approach (Tweney et al 1980).
Mynatt et al 1977
select a path to fire a particle across the screen. Then choose a pair of possible screens to test hypothesis.
Confirmation, disconformation and control groups. (Shoot a particle where you click but its misdirected and you have to figure out why and how to aim it).
Mynatt results.
Confirm: 71%
disconfirm 70%
control 71%
people consistenly chose screens that would confirm their hypothesis. Bare in mind disconfirm group was trained in disconfirming.
Mynatt results.
But 91% of participants changed to a correct
hypothesis when given disconfirmatory evidence
Mitroff 1974
Nasa scientists (N=40) showed confirmation desires. They argued without it many good ideas would die out as a result or premature falsification. These were renouned scientists.
Wasons 246 effect.
large area of correcrness but the subject focuses on a very small area of it.
real world reasoning
shows the opposite of 246 effect as we have a larger rule when the actual rule is a lot smaller
