Problem solving
• Problem solving: cognitive processes focused on
achieving a specific goal.
• Strategies of problem solving: Trial and error,
algorithms and heuristics
• Ill-defined vs. Well-defined problems.
Heuristics vs. algorithms
• Heuristics: general problem solving
strategies that are often useful but not
always effective (in football: control line of
scrimmage, avoid turnovers, in chess:
control center of board.)
• Algorithms: step by step procedures
guaranteed to solve a specific problem
(recipe to bake a cake, formula to solve for
area of triangle)
Examples of Heuristics
• 1. Means-end analysis: breaking problem
down into series of sub-problems.
• 2. Analogies: using past experience as
model for current problem-solving
• Research on use of analogies (past
experience) contradictory.
When is past experience
harmful?
• Dunker (1945) Make a lamp problem.
Thinking—Five Key Barriers to
Problem Solving
• 2. Functional
Fixedness: thinking
of an object as only
functioning in its
usual way
• Can you use these supplies
to mount the candle on the
wall so that it can be lit in a
normal way without toppling
over?
Thinking—Five Key Barriers to Problem Solving
(Functional Fixedness Continued)
• To overcome
functional fixedness,
think of the matchbox,
tacks, and candle all
functioning in new
ways.
When is past experience
harmful?
• Mental set: retaining a old successful
problem-solving procedure even though it
is not effective in its current context. Water
jar example here!
Experimental testing for mental set:
Luchin’s (1942) water jar problem:
When is past experience helpful to problem
solving?
• 1. Gick & Holyoak (1980) studies of
problems solving with and without past
experience
• 2. Chi’s (1985) studies of expertise and
problem solving
Problem solving in Physics professors vs.
students: Problem categorization
Problem solving in Physics professors vs.
students: Problem categorization
Problem solving in Physics professors vs.
students: Problem categorization
• Newell & Simon: General problem solver (GPS); first
attempt at a software program designed as an all
purpose problem solver.
• Key concepts:
– Problem space
– Means –end analysis
– Current state vs. desired state
Thinking—Creativity
• Creativity :ability to produce valued
outcomes in a novel way
• Three elements of creativity:
• Originality
• Fluency
• Flexibility
Thinking—Creativity
• Divergent Thinking: ability to produce
many alternatives or ideas; linked to
creativity (e.g., reordering the letters
“grevenidt” to form many new words)
• Convergent Thinking: attempting to find
one correct answer; linked to
conventional, non-creative thinking
(e.g., 2 + 2 = ?)
Experts and brain level
• fMRI of experts
(A) and novices
(B) engaged in
face portrait
drawing task.
What Is Intelligence?
Historical views of intelligence:
1. Single ability or general factor called “g”
(Spearman)
2. Multiple abilities (Thurstone and
Guilford)
3. Single ability with two types of g, fluid
and crystallized intelligence (Cattell)
4. Multiple abilities (Gardner and
Sternberg)
Intelligence as processing speed
Test stimulus
30-200ms
Mask – L or R? shortest time needed
to reliably make distinction?
• Also can be measure with Posner task A-a match time Low IQ take
25-30ms longer
• First Inspection time=sensory discrimination
• Second Posner time=stm/ltm access
Intelligence Models
• Gardner
• Sternberg