How do experts and novices differ? Flashcards
What is the 10-year rule? (Hayes, 1989)
Ten years of prep are required to attain high levels of skill. This seems to apply to many domains - chess, sports, piano, music composition, poetry, as well as written composition in general
But, might be 10,000 hours rather than 10 years.
What are exceptions to the 10 year rule?
Need appropriate type of practice.
Not mere exposure, but deliberate practice is needed.
In fact, for creativity, there can be too much practice
- Simonton (1991): When looking at 120 eminent composers, he found a negative correlation between age of first preparation and productivity/fame.
- Knowledge can obstruct some creativity
If practice doesn’t necessarily improve skill, how does it benefit us? Refer to Burns (2004)’s correlational experiment between chess players in different games.
Practice improves pattern recognition –> improves speed
Chess played at both fast and slow speeds - does speed make a difference to who wins?
Burns (2004): corr with winning
Fast play: r=.78
Slow play: r=.90
Stronger r/ship between fast and slow play as expertise level increases
What evidence from Savelbergh et al (2002)’s study on soccer players suggest that fast processing appears to be fundamental to the performance of experts?
Highest level of skills: distinguished by their moves within the first few seconds
- Time used to assess alternatives
Having the right representations –> able to find right moves at the start
Sports:
Savelsbergh (2002): semi-pro soccer goalies were more accurate in stopping the balls and had quicker time movement after anticipating location of a ball from watching the lead-up than recreational soccer goalies. However, there was no difference in reaction time
Why are skilled sportspeople faster than novices?
1950s-90s: Assumed that skilled athletes have superior perceptual skills (vision and motor)
Skilled chess players/athletes retain, recall and recog sig more info from structured game situations - have more declarative knowledge and better representation
What did Helsen and Starkes’ (1999) study on the non-specific and soccer-specific skills reveal about the skill differences between experts and novices?
Measured non-/soccer-specific skills for semi-pro/high school players
FOUND:
- No difference in non-specific skills (e.g. Rt), as prev found
- Soccer-specific skills:
- Semi-pro more likely to make the right decisions, made fewer fixations, and focused on the critical aspects of the scene (e.g. defenders and open space)
- High school players: looked at ball, attackers and goal
- Expert search patterns differed between attack/defense
- Superior representations of soccer game –> Pro players make time
What did Chi, Feltvich and Glaser (1981) study on the representation of physics problems reveal about the skill differences between experts and novices?
Physics Novices and Experts classify problems differently.
- Novices (UG): Use surface features
- Experts (PG): Deep structure features
What did Lesgold et al. (1988) study on the representation of medical problems reveal about the skill differences between experts and novices?
What might explain their results?
Medical students vs Radiology experts had to diagnose an x-ray of the lungs.
- Novices: Shadow = tumour (Tumours as most common causes of shadows)
- Experts: Shadow = collapsed lung (Examined boundaries of lungs)
Why?
- Experts used more reasoning, and developed coherent model of patient - built a mental representation of the situation
- Students start out learning to identify features –> thus may make more errors as they start to use deeper recog-triggered reasoning
- Complex representations are often traded off with recall for features: Experienced doctors were more accurate but had poorer recall for diagnosis info (Patel & Groen, 1991)
Experts think about their field differently.
What did Bierdeman and Shiffrar’s (1987) experiment on chicken sexing teach about whether or not representation can be taught?
Very vigorous training to divide chicks into one sex or another
- 2-6 years of practice –> high accuracy (98%)
Bierderman and Shiffrar (1987) gave participants identification sheets that broke the task down into different sections, and asked them to sex chicks
- 84% accuracy.
- Breaking task down helped make a complex task learnable
- Right representation may substitute for years of practice - Shortcut!
In what way do innate differences determine the limits of expertise? What is the evidence against a lack of innate predictors? Refer to studies by Galton (1869), g, Terman IQ.
Hereditary: Galton (1869) found evidence that genius ran in families with a background of geniuses. But may have confused nature with nurture (only possible to be good muso if they had financial resources - envr/fam background seemed to play a role)
Genetic influence on “g” - as high as 60%. Greatest in adulthood
Terman: No evidence that n=1000 kids with IQ > 140 became geniuses.
Howe et al (1998): No reliable measure of innate predictors of talent (e.g. early performance in music exams - not good predictor of best musicians)
- Family background plays a role
Twin studies do not predict genius
May need min level of general traits relevant to specific tasks - but no predictiveness in variance beyond this
Personality traits (e.g. nAch, conscientiousness) may help - conscientiousness linked to success (requires persistence to get to the top)
In what way does motivation determine the limits of expertise? (birthdays)
Motivation drives persistence and practice in achieving expertise
- But: If you are skilled, then you will also be motivated to get better
Motivation/Ability causality determined through age-related effects
BIRTHDAYS
Barnsley et al (1985): Birthdays of Canadian ice hockey players most likely in January (cutoff date) - Players near the cutoff date often bigger/better than opponents –> motivated to get better
Belgium: Changed cutoff date from Aug 1st to Jan 1st
- Distrib of birthdays fairly even across year
- Birthday distrib shifted according to shift of cutoff day
Strong evidence that birthday distrib limits expertise, not motivation
In what way does the type of practice engaged determine the limits of expertise?
??
Summary for Expertise/Skill data (revision lel)
Practice is critical, shows regular relationship to improvement when based on refinement of procedures (power law of practice)
Complex skills: Practice leads to better representation (larger chunks, focus on critical features, better representation of situation)
Skilled action seems very based on pattern recognition
Motivation is critical (to push for practice)
What does Ericsson’s (2003) theory propose about the limits of expertise?
Rejects Galton: Performance is not constrained by innate, fixed capacities – Infinite Modifiability
Mediating bio mechanisms and obs performance can still be improved substantially even when individuals are highly experienced (with appropriate practice)
Expert performance mediated by complex modifiable representations –> allows experts to exhibit faster speed, superior selection, and more precise motor execution
Models off a computer: (refer to diagram)
Hardware (fixed) Software (modifiable): Machine
Interacts with Bioware (people)
- Idea of neuroplasticity
- Does not make distinction between physical and mental skills
What evidence is there to support Ericsson’s Theory (2003)? Refer to Ericsson, Chase and Faloon (1980) on digit span increase, Maguire et al (2000) hippocampus taxi.
Change occurs by incremental extension beyond previous limit.
- Body strained –> maintain homeostasis
- Animal brains change due to different types of physical activities
Ericsson, Chase and Faloon (1980): Increased digit span from 7 to 79
Push-ups: able to reach >10,000
Maguire et al. (2000): Neural structural differences in brains of London taxi drivers
- Bigger posterior Hippocampi, smaller anterior
