Motor Control and Motor learning
Blocked Versus Random PracticeKelly Moberly, Kristen Sanchez,
Bryan Duran, Elizabeth Swift, Chelsea Zemmin, Andrew Trevino
What is Blocked and Random practice?Blocked PracticeA systematic
repetition of a given skill during the practice periodA, A, A, B,
B, B, C, C, CRandomized PracticeA random and usually an unknown
order during the practice periodA, C, B, B, C, A, B, A, C
Blocked Practice
The systematic nature of blocked practice results in better
acquisition.When tested for retention (a way to measure learning)
the subject will often perform worse.
Random PracticeThe variability of randomized practice often
appears as worse learning in the acquisition stage.When tested for
retention, this group typically performs better than there blocked
group counterpart.
Some theories to explain why Random practice results in better
learningContextual Interference/ Forgetting ExplanationSchmidt and
Wrisenburg believe that by randomizing practice you are increasing
contextual interference. Contextual interference occurs when the
task is varied. When practice is randomized and contextual
interference is introduced the subject must stay cognitively alert
to adjust to the changing task demands. Shea and Morgan argue the
forgetting explanation also causes the subject to rework the
challenge they were just faced with (similar to contextual
interference)
Elaboration HypothesisShea and Zimny argue that varying the
practice allows the participant to find differences between the
skills. When blocked practice is performed the subject does not get
the opportunity to differentiate between the skills. This will
result in less learning than those who utilize random practice.
For exampleCuddy and Jacoby used this example to show how
randomized practice promotes better learning due to contextual
interference and forgetting experience:Imagine you are a 10 year
old learning to divide (a novel task)You are asked to divide 12 by
4, 21 by 7, and 18 by 2
If the child used blocked practice by repeating the same problem
three times in a row, they are really only solving the problem
once. The next two responses are likely due to memory.However, if
we asked the child to solve the problems in a random order
(introducing contextual interference) then they are more likely to
have to re-solve the problem instead of relying so heavily on their
short term memory.
Our HypothesisBased on the literature we expectedthe two
subjects using blocked practice to perform better in acquisition
and worse in retention. The oppositeis typically expected in the
subjectsperform random practice.
Our experimental design4 subjects with no previous, extensive
basketball experience3 females, 1 maleOutdoor courts on campus
(Anschutz Medical Campus)Used the same size basketball for all
trials
Our Experimental Design
Blocked PracticeRandom PracticeSubjects2 subjects2
subjectsPractice trials2 sets of 50 trials2 sets of 50 trialsOrder
of trials10 trials at each location, repeated twice10 trials at
each location, practiced in an unknown order to the subject
Visual representation of the 5 locations of the basketball
court
Our experimental designTest of Retention 10 shots from the
free-throw lineTest for Transfer10 shots from the free-throw line,
using a volleyball
Acquisition stageFigure 1 shows the number of shots made out of
50 for each participant during two practice sessions. The blue
lines represent the subjects who performed random practice, and the
red lines represent the group that performed blocked practice.
Results: Retention and Transfer
Figure 2 shows the number of free-throws made by each
participant during our baseline trial (trial 1), our first
retention trial (trial 2), and our second retention trial (trial
3). Trial 5 is a transfer test of a free-throw with a basketball.
Four participants scored a 1/10 and one participant scored a 4/10
on the transfer test.
Ball so hard
So why DID our experiment not match? More extensive test of
retention (did not allow for a warm-up)A more variable scoring
system to show more slight improvement (Rim shots, backboard,
etc)More feedback from coaches during initial training session due
to the range of previous experience Larger sample size
How do we maximize learning in physical therapy?IT DEPENDS
Is it a complex and novel skill? Consider Blocked Practice Is it
a novel skill with the ability to alter CI? Consider Random
PracticeDoes the patient need to perform a skill with variability?
Consider Random Practice Is the skill primarily a target skill
(volleyball/golf/ tennis)? Consider Random PracticeHelping a
patient recovering from a stroke? Consider Random practice, unless
contextual interference is too high
