Practice

1
Practice

• Chapter 5

2
Performance learning

• Performance is observed, learning inferred
• Performance can improve without improved learning
• Learning can improve without improved performance
• What is learning, really?

3
Amount of practice

• Do we become less dependent on the environment,
  or more?
• Important implications do you practice
  powerlifting in front of a mirror to aid form?
  (Proteau Temblay, 1998)

4
Amount of practice

• As we learn, do we rely less on feedback?
• Proteaus task (1987, 1992)...

5
Amount of practice

• As we learn, do we rely less on feedback?
• Proteaus typical paradigm...
• Task 90cm movement in 550msec
• Condition 1 200 trials with vision
• Condition 2 2000 trials with vision
• Test condition No vision

Has also used walking (see next slide), force
control, and others
Sometimes as little as 20 vs. 200 trials too.
6
Amount of practice

• As we learn, do we rely less on feedback?
• Typical Results

The full vision practice condition typically
transfers to a no vision condition badly, and
this gets worse as full vision practice increases
7
Amount of practice

• As we learn, we seem to rely more on the
  information that is present and used when we
  learn
• For the powerlifting form example mirrors not a
  good idea (Proteau Tremblay, 1998)
• Also think of learning to type, drive (shifting
  gear), play piano (watching fingers) and so on
• learning is specific to the source or sources of
  afferent information that are more likely to
  ensure optimal performance

8
Amount of practice

• More recent findings
• Weak vs. strong visual cues (still a reaching
  task) weak vision transfers as well as no
  vision to a no vision condition
• Weak vision encourages processing of other
  sources of information like proprioception

9
Amount of practice

• More recent findings
• Ball interception touch the interception point
  of a moving ball with the index finger
• Two conditions full vision, or ball only

10
Amount of practice
Normal specificity effect when transferring to
practiced trajectories

• More recent findings
• Ball interception touch the interception point
  of a moving ball with the index finger
• Two conditions full vision, or ball only

Effect disappears in new trajectories
11
Variability of practice

• Imagine youre trying to teach catching
• Should you make it as simple as possible, by
  choosing only one type of ball, one type of
  throw, one catching techniqueetc
• Or not?

12
Variability of practice

• Schema Theory (Schmidt, 1975)
• More variability means more generalized schema
  for learning
• Like a regression rule
• Your performance of the right movement depends on
  the proximity of previous behavior to the desired
  behavior

13
Variability of practice

• Supported?
• Generally, Id say so, provided key assumptions
  are met
• Are the participants genuinely novices?
• Is sufficient practice given to form a strong
  enough prediction rule?
• Is prediction of a novel version of the task
  ultimately required?
• See Schmidt and Shapiro (1982) for a summary
• Does not imply that the governing theory is
  accepted
• Now as for organization of variability...

14
Contextual interference

• Practice order (3 tasks A, B, and C)

Low
Amount of contextual interference
High
15
Contextual interference

• Practice order (3 tasks A, B, and C)
• Stimulus light goes off
• Color signifies which movement pattern to perform
• Pick up tennis ball
• Knock down barriers
• Replace tennis ball
• RT and MT measured

16
Contextual Interference effect

• From the classic study (Shea Morgan, 1979)
• Practice Low CI is better (time is being
  measured, so smaller scores are better)
• Retention High CI is better

17
Contextual Interference

• Theory
• 2 primary hypotheses
• Elaboration
• Compare the sequence of tasks practiced within
  blocked and random practice what kinds of
  comparisons between or among the tasks are
  promoted by each type of practice?

18
Contextual Interference

• Theory
• 2 primary hypotheses
• Action plan reconstruction
• Compare the sequence of tasks practiced within
  blocked and random practice how long, on
  average, do you have to wait before the task is
  repeated in each practice order?
• Brown-Peterson (1958), Peterson-Peterson (1960)

Recall worsens as interval A increases
A
Recall improves (!) as interval A increases
A
19
Contextual Interference

• Some research examples, and some conclusions...

http//www.youtube.com/watch?vCIG3El76ltgfeature
related
20
Contextual Interference

• Smith Davies (1995)
• Used a Pawlata roll
• Compared progressive part learning of a full roll
  with either alternate (high CI) or blocked (low
  CI) practice
• All transferred to both a full and a half roll
  one week later (score is 5 - average attempts
  prior to success)

21
Contextual Interference

• Now for something completely different (...and
  quite a bit more difficult)

Well see that these findings may severely limit
the generalization of the CI effect
22
Contextual Interference

• Task
• Notice overall duration varies across tasks
  relative timing does not

23
Contextual Interference

• Task
• With this task, you can vary overall duration
  without varying rhythm
• see previous slide
• Or both
• Or vice versa
• E.g.
• 300-200-400
• 400-300-200
• and 200-300-400

24
Contextual Interference

• Findings
• Experiment 1
• The more consistent the practice type, the better
  people perform in retention and transfer

25
Contextual Interference

• Findings
• Experiment 2
• Feedback type has a radical effect on this
  outcome
• Hard to see, but depending on fdbk, effect is
  almost reversed
• Generally, whatever results in stability of RT
  during practice works (random practice with
  segment fbdk did this, so did blocked practice
  w/ratio fdbk)

26
Contextual Interference

• Since then...
• Still celebrated as a general effect
• Does not seem to be the case
• Sheas ( colleagues) work clearly important
• Findings largely limited to overall timing
  (simple adaptations of already known movements)
• Smith Davies (1995, see also Smith, 2002, Smith
  et al, 2003) may be a result of negative transfer
  rather than CI
• But these things matter too!
• Subsequent work emphasizes the disconnect between
  simple and complex tasks...

27
Contextual Interference

• Complexity as a moderator (for CI others)

A good review paper for the final
28
Part vs. Whole practice

• Segmentation, fractionation, simplification,
  component interdependence...
• Do the parts fit together naturally, or can they
  be easily separated?
• Think of a free throw should you practice the
  knee movement and the arm movement separately?
• Juggling...from the annals of 257 (Spring 2000)
  Knapp Dixon (1952) revisited.

29
Part vs. Whole practice
11am class move through practice stages quickly
(get to the full juggling phase as soon as
possible) 1235pm class practice each stage
thoroughly (master each stage before moving on)
Similar findings have been published by Knapp
Dixon, 1952.
30
Part vs. Whole practice

• In this case, part practice of juggling didnt
  work well
• Seems that the skill is highly organized, and as
  such should not be practiced in parts
• See also Hautala (1988) scarves not a good idea.