1. Practice Variability and Specificity
Chapter 16
Practice Variability and Specificity
Concept: Variability of practice experiences is important for learning motor skills

2. Practice Variability
Refers to the variety of movement and context characteristics the learner experiences while practicing a skill
Movement and context characteristics that can be varied in practice:
Skill variations that will be required in “test” conditions
Physical context in which the skill is performed
Situation in which the skill occurs

3. The Future Performance Benefit of Practice Variability
Research evidence shows that more practice variability is better for learning and performance in future “test” situations than less variability
Practice variability benefit can be related to the increased amount of performance error during practice

4. Shea and Kohl Goal: Learn to use 175 N of force to press a handle
Constant practice group – practiced using 175N for 289 trials
Variable practice group – practiced producint four different amounts of force
125N, 150N 200N, 225N (175N not practiced)
Retention/transfer test for 175N: variable group performed more accurately

5. The Future Performance Benefit of Practice Variability
Research evidence shows that more practice variability is better for learning and performance in future “test” situations than less variability
Practice variability benefit can be related to the increased amount of performance error during practice

6. How to Implement Practice Variability?
Assess characteristics of the physical context and skill characteristics of that performance
Vary these characteristics according to the type of skill being learned
Practice conditions to vary for closed skills
See Table 16.1
Practice conditions to vary for open skills

7. How to Implement Practice Variability?
Assess characteristics of the physical context and skill characteristics of that performance
Vary these characteristics according to the type of skill being learned
Practice conditions to vary for closed skills
See Table 16.1
Practice conditions to vary for open skills

8. Organizing Variable Practice
Is there a best way to organize practice variability?
See 3 options in Figure 16.2
Answer can be determined from applying the learning phenomenon known as the contextual interference effect

10. Organizing Variable Practice
Is there a best way to organize practice variability?
See 3 options in Figure 16.2
Answer can be determined from applying the learning phenomenon known as the contextual interference effect

11. Contextual Interference
The memory and performance disruption that results from performing variations of a skill within the context of practice
Originally described by Battig (1979)
Various amounts of contextual interference can occur during practice depending on the scheduling of the practice variability
see Figure 16.3
The contextual interference effect occurs when higher amounts of contextual interference are involved in practice than lower amounts

13. Contextual Interference
The memory and performance disruption that results from performing variations of a skill within the context of practice
Originally described by Battig (1979)
Various amounts of contextual interference can occur during practice depending on the scheduling of the practice variability
see Figure 16.3
The contextual interference effect occurs when higher amounts of contextual interference are involved in practice than lower amounts .

14. Research Evidence for the Contextual Interference Effect
Laboratory experiments
Shea & Morgan (1979) – 1st demonstration of the effect for learning motor skills
Non-laboratory experiments
Beginners learning multiple skill variations
Magill & Goode (1986) – badminton serves
Skilled athletes practicing to improve performance of multiple skill variations
Hall et al. (1994) – baseball players hitting different types of pitches

16. Research Evidence for the Contextual Interference Effect
Laboratory experiments
Shea & Morgan (1979) – 1st demonstration of the effect for learning motor skills
Non-laboratory experiments
Beginners learning multiple skill variations
Magill & Goode (1986) – badminton serves
Skilled athletes practicing to improve performance of multiple skill variations
Hall et al. (1994) – baseball players hitting different types of pitches

17. Contextual Interference and Judgments about Learning
A characteristic of blocked practice schedules:
Learners overestimate their learning
Performance during practice misleads them to judge they are learning more than they actually are
See experiment by Simon & Bjork (2001)

18. Limits of the Contextual Interference Effect
Research shows much support for the contextual interference effect but also shows that it does not apply to all motor skill learning situations
Characteristics related to the limits of the effect:
Motor skill characteristics
Learner characteristics

19. Limits of the Contextual Interference Effect
Research shows much support for the contextual interference effect but also shows that it does not apply to all motor skill learning situations
Characteristics related to the limits of the effect:
Motor skill characteristics
Learner characteristics

20. Why Does the Contextual Interference Effect Occur?
Two predominant hypotheses
Elaboration Hypothesis: The effect is related to the elaboration of the memory representation of the skill variations that a learner is practicing (Shea & Morgan, 1979) (Engages in more strategies-compare and contrast)
Action Plan Reconstruction Hypothesis: High amounts of contextual interference benefit learning because the interference requires a person to reconstruct an action plan on subsequent practice trials for each skill variation (Lee & Magill, 1985)

21. Why Does the Contextual Interference Effect Occur?, cont’d
Regardless of which hypothesis, two important characteristics have been demonstrated:
Higher levels of contextual interference involves greater attention demands during practice
People who practice according to a blocked schedule tend to overestimate how well they are learning during practice

22. Practice Specificity Specificity of practice hypothesis
Test performance is directly related to the similarity between characteristics of the practice and test conditions
Is this hypothesis at odds with the contextual interference effect?
Agreement that the hypothesis applies to three characteristics of the practice and test conditions

23. Practice Specificity, cont’d
3 Practice – Test characteristics related to the practice specificity hypothesis:
Sensory/perceptual characteristics
Performance context characteristics
Cognitive processing characteristics