Thinking and reasoning Flashcards
What does thinking include?
- deductive reasoning
- inductive reasoning
- problem-solving
what is deductive reasoning
from premises, generate a valid conclusion
what is inductive reasonign
predicting the future from past data
What is the dual process theory
We use two kinds of process
- sequential, conscious, rational
- automatic, unconscious, fast
What is ‘system 1’
Intuitive, automatic, largely unconscious, fast-and-frugal, quick-and dirty, approximate — but domain-specific— procedures, schemas, rules of thumb or heuristics, that
» are adaptive and mostly effective when applied in the appropriate domain, but
» are only approximate – with some built in biases
» may lead to error if applied to an inappropriate domain
What is system 2
A slow, clunky, sequential, effortful —but rational, logical, general-purpose – conscious reasoning system
» constrained by limited working-memory capacity and other basic limitations of our cognitive machinery
What is the availability heuristic?
judge as more probable/ frequent events/objects of which more examples are readily “available”
why does Tversly and Kahneman say the availabiltiy heuristic works>
because it is generally easier to retrieve from memory examples of events/objects that are more frequent
retrievability is also determined by…
- recency
- salience
- similarity to the current case
What is availability bias?
to over-estimate probability of events of which we know examples that easily retrievable — e.g because recent, personally salient, or similar to present instance
example of availability bias?
» overestimate the risks of dying of rarer (but dramatic, reported) causes, such as botulism, floods, tornados, and measles, but underestimate the risks of dying of common causes, such as strokes, cancers, diabetes. (Slovic et al, 1980)
What is representative bias?
• If something/someone has features representative of being an X, we tend to think that they have the standard properties of an X
prototype effect
• I have a weighted coin that lands head-up 4 times out of 5 and you know this. I ask you to predict a series of tosses: you will get a £1 for each correct prediction. What ought you to predict?
what do participants do
Not: H on 80% of trials and T on 20%! Should do H every time to maximise chances
what did Duncker find when asked subjects to find a way of supporting a lighted candle on a vertical wooden wall, given these props: candle and pins
• They were less successful than subjects given the same problem but with the drawing pins tipped out of the box.
What is Watson’s 2 4 6 experiment?
This sequence – 2, 4, 6 – is generated by a rule. You have to try to guess the rule, by trying out other sequences.”
» Participant then has to generate further sequences of three numbers, receiving feedback: “yes: fits the rule”or “no: doesn’t fit”
» and declare his/her hypotheses about what the rule is.
what did watson find
• Participants tend to offer over-specific hypotheses, e.g. “The numbers increase by steps of 2”, and (more important)
» (a) are reluctant to abandon their hypotheses (are conservative)
» (b) tend to seek confirmatory rather than disconfirmatory evidence.
• Can’t falsify by doing this
• Scientists just as prone to these errors as others!
if a problem is soluble, there is…
at least one path through state space between the start and the goal states
what must the problem solver do
search for operators that will:
• move her/himself through intermediate states on a path approaching the goal,
• avoid the need for backing up from dead-ends, or going round in circles
• minimise the path length
how does working memory limit are solving
• Given a huge “workspace” and time we could exhaustively enumerate all the possible legal “moves”, and pick the shortest path.
(cf IBM’s “Big Blue” playing chess).
• But we don’t have the working memory capacity for this:
how can we get over our limited capacity?
use heuristics such as
- means-end analysis
- dont-repeat-a-move-if-possible
what is means-end-analysis
pick a general means for reaching the goal; if that means is not yet available, create the sub-goal of achieving that means
what are design limitations in cognitive capacities
» lead to reliance on heuristics (approximate rules of thumb) and
» result in intrinsic biases when we apply these heuristics
What is Watson’s 4-card problem
All cards have a letter on one side and a number on the other. Which two cards have to be turned over to check whether the following rule is true?
IF A CARD HAS A VOWEL ON ONE SIDE,
THEN IT HAS AN ODD NUMBER ON THE OTHER SIDE
what do participants in the 4-card problem do
Student subjects always choose “A” [as they should] but tend also to choose “1” rather than “2”.
what is deontic reasonign?
IF-THEN happens to have the same truth conditions as logical IF-THEN
