Transcript Deductive Reasoning - University of California, Irvine

Skill Learning and Expertise
Anderson’s ACT Theory
• General theory of learning and problem solving
• Anderson (e.g., 1983, 1990, 1993, 1996)
– Adaptive Control of Thought (ACT)
– Various forms: ACT*, ACT-R
– Rely on notion of production systems
A schematic diagram of the major components
If information in working memory matches production rule condition, then
fire production rule
Skill Learning in ACT
• Theory claims that cognitive skills are realized by
production rules
• Knowledge initially enters in declarative form
e.g., instructions for how to drive a car
• Transformed into procedural knowledge
e.g., skilled driving
Speed of solution of
alphabet arithmetic
problems as a
function of stage of
practice and size of
addendum (add 2,
3, or 4).
Data from Zbrodoff
(1995).
Developing Expertise
• What are differences between novices and experts?
• How to become an expert?
• Speed of learning
Experts excel mainly in their own domains
• experts are masters in their own domain
•
the skill does not cross into different domains
(Chi, Glaser, and Farr, 1988; Ericsson and Charness, 1997)
Experts perceive large meaningful patterns
in their domain
• Experts have extensive knowledge. Allows them to
notice meaningful patterns
– Chess masters excel in their recall of the clusters of
pieces that they see.
– Programmers can recall key programming language
words in meaningful clusters.
• top-down processes -- giving meaning to what it is we
see
(Chi, Glaser, and Farr, 1988)
See anything unusual?
(collapse of the upper right lobe, upper left in picture)
(normal)
• Experts need only a few seconds to see what is
wrong (or what isn’t)
• Experts augment these incomplete images with
extensive background information
Chess Studies
• De Groot (1965)
• Instructed 5 chess grandmasters to think out loud
• Grandmasters only considered about 30 moves and only
thought 6 moves ahead.
• Not that different from novices. However, masters spend
more time on good moves.
• Masters rely on extensive experience: 50,000 patterns
Chase & Simon (1973)
Actual Board Position
Random Board Position
Conclusion from Chase & Simon (1973)
• Chess masters only expert with real chess positions.
They do not have better memory in general
• Expertise allows chunking of salient information to
promote memory of good moves
• Experts organize knowledge differently – reflects a deep
understanding.
Increasing Your Digit Span
• Number of digits that can be repeated after one presentation
1 4 0 1 9 2 1 0 1 …..
• Normal digit span = 7 or 8 digits (phone number). Encoding
strategies help
1 4 0 1 9 2 1 0 1 …..
P140
number of
this class
P192 another
number of
this class
Room
number for
class
Growth in memory span for one subject (S.F.) with practice
Memory span for digits can be trained
you too can have a 80 digit memory span
Experts see and represent a problem in their
own domain at a deeper level than novices…
• Experts see structural similarities
• Novices see surface similarity
(Chi, Glaser, and Farr, 1988)
Novices group these
Experts group these
Chi, Feltovich, and Glaser, 1981)
What makes an expert an expert?
• Talent? IQ? Practice? Genetic factors?
• Study exceptional feats:
– Memory experts
– Chess experts
– Musicians
– Athletes
General & Inherited Factors
IQ tests*
Short-term memory
Speed of reading
Reasoning ability
Attention
Do not predict
superior performance in a
particular domain
Experts are not better problem solvers in general. Expertise
is domain specific
* IQ tests might predict some success in high-complexity jobs (e.g. scientist)
10 year rule
• 10 years of deliberate practice needed to attain an
international level: not simply engaging in activity, but
practicing in an effortful, intensive, self-monitored mode
• Master chess players spend 10,000 – 20,000 hours
playing
What about talent?
• Maybe exceptional performance in some area can be
explained by talent – an innate predisposition that
predetermines performance in a domain.
• Anders Ericsson et al.
 disagree that concept of talent is useful or explains
anything
(genius is 90% perspiration and 10% inspiration)
 this is controversial!
What about musical talent?
• Absolute pitch:
– Most musicians acquired it for their own instruments
– Can be improved by training
Difference between good and exceptional musicians is
related to the amount of practice
Graph from Ericsson et al. (1996) showing the cumulative amount of practice by
two groups of aspiring musical performers (experts and good violinists) and those
who planned to teach music
The Power Law of Practice
• The more practice, the easier a task becomes. How
does a skill improve over time?
• Ubiquitous finding: skill improves as power function of
amount of practice
Time to complete task
Log( Time to complete task )
T  cP
Amount of practice
Time to
complete task
a
constant
Amount of
Practice
Log( Amount of practice )
Constant
(Slope)
Cigar rolling ability over
10 years of working in a factory
Initial large
improvements
decrease with time
 Very difficult to
improve any further
power law of
practice
(Crossman, 1959)
Learning to Mirror Reverse Read
(Kolers, 1979)
(Kolers, 1979)
Practice increased brain size
• Hippocampus & London Taxi Drivers
• Brain scans reveal that taxi drivers have much larger
posterior hippocampus than controls
• Maguire et al. 2000