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In this section, we focus on important issues concerning the content of augmented feedback, and then examine several types of augmented feedback that practitioners can use. We consider five issues related to the content of augmented feedback. Each of these concerns some of the kinds of information augmented feedback may contain.
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Information about Errors versus Correct Aspects of Performance
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An often debated issue about augmented feedback content is whether the information should refer to the mistakes made or those aspects of the performance that are correct. Research consistently has shown that error information is more effective for facilitating skill learning, especially in terms of persistence of learning and transfer capability. This evidence supports an important hypothesis, that focusing on what is done correctly while learning a skill, especially in the early stage of learning, is not sufficient by itself to produce optimal learning. Rather, the experience the person has in correcting errors by operating on error-based augmented feedback is especially important during skill acquisition to enhance future performance of the skill in different environments and situations, as well as to enhance the capability to self-correct errors while performing the skill.
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Another way of looking at this issue is to consider the different roles augmented feedback plays. Error information directs a person to change certain performance characteristics; this in turn facilitates skill acquisition. On the other hand, information indicating that the person performed certain characteristics correctly tells the person that he or she is on track in learning the skill and encourages the person to keep trying. When we consider augmented feedback from this perspective, we see that whether this feedback should be about errors or about correct aspects of performance depends on the goal of the information. Error-related information works better to facilitate skill acquisition, whereas information about correct performance serves better to motivate the person to continue. Although some researchers have argued that information about correct performance has a more direct effect on learning than has been acknowledged to date (Chiviacowsky & Wulf, 2007; Wulf et al., 2010), the primary role for information about correct performance as augmented feedback is motivational.
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A CLOSER LOOK KP about Certain Features of a Skill Helps Correct Other Features
Participants in an experiment by den Brinker, Stabler, Whiting, and van Wieringen (1986) learned to perform on the slalom ski simulator, like the one illustrated in the preceding chapter in figure 14.2. Their three-part goal was to move the platform from left to right as far as possible at a specific high frequency, and with a motion that was as fluid as possible. On the basis of these performance goals, three groups received different types of information as KP after each trial: the distance they had moved the platform, how close they were to performing at the criterion platform movement frequency, and how fluid their movements were (i.e., fluency). All three groups practiced for four days, performing six 1.5 min trials each day, with a test trial before and after each day's practice trials.
Early in practice, the type of KP an individual received influenced only the performance measure specifically related to that feature of performing the skill. However, on the last two days of practice, KP about distance caused people to improve all three performance features. Thus, giving KP about one performance feature led to improvement not only of that one, but also of the two other performance features.
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Two relevant questions concerning the comparison of the use of KR and KP in skill learning situations are these: Do practitioners use one of these forms of augmented feedback more than the other? Do they influence skill learning in similar or different ways?
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Most of the evidence addressing the first question comes from the study of physical education teachers in actual class situations. The best example is a study by Fishman and Tobey (1978). Although their study was conducted many years ago, it is representative of more recent studies, and it involves the most extensive sampling of teachers and classes of any study that has investigated this question. Fishman and Tobey observed teachers in eighty-one classes teaching a variety of physical activities. The results showed that the teachers overwhelmingly gave KP (94 percent of the time) more than KR.
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An answer to the second question, concerning the relative effectiveness of KR and KP, is more difficult to provide because of the lack of sufficient and conclusive evidence from research investigating this question. The following examples of experiments provide some insight into a reasonable answer.
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Two of the experiments suggest that KP is better than KR to facilitate motor skill learning. Kernodle and Carlton (1992) compared KR with videotape replays and verbally presented technique statements as KP in an experiment in which participants practiced throwing a soft, spongy ball as far as possible with the nondominant arm. KR was presented as the distance of the throw for each practice trial. The results showed that KP led to better throwing technique and distance than KR. Zubiaur, Oña, and Delgado (1999) made a similar conclusion in a study in which university students with no previous volleyball experience practiced the overhead serve in volleyball. KP was specific information about the most important error to correct as it related to action either before hitting or in hitting the ball. KR referred to the outcome of the hit in terms of the ball's spatial precision, rotation, and flight. The results indicated that KP was more influential for learning the serve.
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However, a study by Silverman, Woods, and Subramaniam (1999) provided evidence for the benefit of both KR and KP in terms of how each related to how often students in physical education classes would engage in successful and unsuccessful practice trials during a class. They observed eight middle school teachers teaching two classes each in various sport-related activities. The results indicated that teacher feedback as KR and as KP showed relatively high correlations with the frequency of students engaging in successful practice trials (.64 and .67, respectively).
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These studies indicate that both KR and KP can be valuable for skill learning. Consider some conditions in which each of these forms of augmented feedback would be beneficial. KR will be beneficial for skill learning for at least five reasons: (1) Learners often use KR to confirm their own assessments of the task-intrinsic feedback, even though it may be redundant with task-intrinsic feedback. (2) Learners may need KR because they cannot determine the outcome of performing a skill on the basis of the available task-intrinsic feedback. (3) Learners often use KR to motivate themselves to continue practicing the skill. (4) Providing only KR may help to establish a discovery learning practice environment in which learners are encouraged to engage in trial-and-error problem-solving activity as they acquire a skill. (5) Providing only KR may help to ensure that learners adopt an external focus of attention as they practice a skill. (See Wulf, Chiviacowsky, Schiller, & Ávila, 2010, for a discussion of the potential benefits of using augmented feedback to induce an external focus of attention during practice.)
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On the other hand, KP can be especially beneficial when (1) skills must be performed according to specified movement characteristics, such as gymnastics stunts, springboard dives or ballet movements; (2) specific movement components of skills that require complex coordination must be improved or corrected; (3) the goal of the action is to produce a specific kinematic, kinetic, or muscle activity profile; (4) KR is redundant with the task-intrinsic feedback.
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Qualitative versus Quantitative Information
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Augmented feedback can be qualitative, quantitative, or both. If the augmented feedback involves a numerical value related to the magnitude of some performance characteristic, it is called quantitative augmented feedback. In contrast, qualitative augmented feedback is information referring to the quality of the performance characteristic without regard for the numerical values associated with it.
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For verbal augmented feedback, it is easy to distinguish these types of information in performance situations. For example, a therapist helping a patient to increase gait speed could give that patient qualitative information about the latest attempt in statements such as these: "That was faster than the last time"; "That was much better"; or "You need to bend your knee more." A physical education teacher teaching a student a tennis serve could tell the student that a particular serve was "good," or "long," or could say something like this: "You made contact with the ball too far in front of you." On the other hand, the therapist could give the patient quantitative verbal augmented feedback using these words: "That time you walked 3 seconds faster than the last time," or, "You need to bend your knee 5 more degrees." The teacher could give quantitative feedback to the tennis student like this: "The serve was 6 centimeters too long," or "You made contact with the ball 10 centimeters too far in front of you."
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Practitioners also can give quantitative and qualitative information in nonverbal forms of augmented feedback. For example, the therapist could give qualitative information to the patient we have described by letting him or her hear a tone when the walking speed exceeded that of the previous attempt or when the knee flexion achieved a target amount. The teacher could give the tennis student qualitative information in the form of a computer display that used a moving stick figure to show the kinematic characteristics of his or her serving motion. Those teaching motor skills often give nonverbally presented quantitative information in combination with qualitative forms. For example, the therapist could show a patient a computer-based graphic representation of his or her leg movement while walking along, displaying numerical values of the walking speeds associated with each attempt or the degree of knee flexion observed on each attempt. We could describe similar examples for the tennis student.
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How do these two types of augmented feedback information influence skill learning? Although the traditional view is that quantitative augmented feedback is preferred, results from an experiment by Magill and Wood (1986) suggest a different conclusion. Each participant practiced moving his or her arm through a series of wooden barriers to produce a specific six-segment movement pattern. Each segment had its own criterion movement time, which participants had to learn. Performance for the first sixty trials showed no difference between qualitative and quantitative forms of KR. However, during the final sixty trials and on the twenty no-KR retention trials, quantitative KR resulted in better performance than qualitative.
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These results suggest that people in the early stage of learning give attention primarily to the qualitative information, even when they have quantitative information available. The advantage of this attention focus is that the qualitative information provides an easier way to make a first approximation of the required movement. Put another way, this information allows learners to perform an action that is "in the ballpark" of what they need to do, which, as we discussed in chapter 12, is an important goal for the first stage of learning. After they achieve this "ballpark" capability, quantitative information becomes more valuable to them, because it enables them to refine characteristics of performing the skill that lead to more consistent and efficient achievement of the action goal. It is important to keep in mind that there are limits to learners' abilities to use quantitative feedback to change their movement patterns. Giblin, Farrow, Reid, Ball, and Abernethy (2015) recently showed that skilled junior tennis players could only execute a limited number of feedback-based instructions to improve their service action. The players' ability to implement more precise instructions was apparently limited by their kinesthetic sensitivity.
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Augmented Feedback Based on Error Size
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A question that has distinct practical appeal is this: How large an error should a performer make before the instructor or therapist gives augmented feedback? To many, it seems reasonable to provide feedback only when errors are large enough to warrant attention. This approach suggests that in many skill learning situations, practitioners develop performance bandwidths that establish performance error tolerance limits specifying when they will or will not give augmented feedback. When a person's performance is acceptable (i.e., within the tolerance limits of the bandwidth) the practitioner does not give feedback. But if the performance is not acceptable (i.e., the amount or type of error is outside the bandwidth) the practitioner gives feedback.
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Research supports the effectiveness of the performance bandwidth approach. For example, in the first reported experiment investigating this procedure, Sherwood (1988) had participants practice a rapid elbow-flexion task with a movement-time goal of 200 msec. One group received KR about their movement-time error after every trial, regardless of the amount of error (i.e., 0 percent bandwidth). Two other groups received KR only when their error exceeded bandwidths of 5 percent and 10 percent of the goal movement time. The results of a no-KR retention test showed that the 10 percent bandwidth condition resulted in the least amount of movement time variability (i.e., variable error), whereas the 0 percent condition resulted in the most variable error. Other researchers have replicated and extended these results (e.g., Cauraugh, Chen, & Radlo, 1993; Coca-Ugrinowitsch et al., 2014; Lee, White, & Carnahan, 1990).
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quantitative augmented feedback augmented feedback that includes a numerical value related to the magnitude of a performance characteristic (e.g., the speed of a pitched baseball).
qualitative augmented feedback augmented feedback that is descriptive in nature (e.g., using such terms as good, long), and indicates the quality of performance.
performance bandwidth in the context of providing augmented feedback, a range of acceptable performance error. Augmented feedback is given only when the amount of error is greater than this range.
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A CLOSER LOOK Quantitative versus Qualitative Augmented Feedback and the Performance Bandwidth Technique
Cauraugh, Chen, and Radlo (1993) had subjects practice a timing task in which they had to press a sequence of three keys in 500 msec. Participants in one group received quantitative KR about their movement times (MT) when MT was outside a 10 percent performance bandwidth. A second group, in the reverse of that condition, received quantitative KR only when MT was inside the 10 percent performance bandwidth. Two additional groups had participants "yoked" to individual participants in the outside and inside bandwidth conditions. Members of these two groups received KR on the same trials their "yoked" counterparts did. This procedure provided a way to have two conditions with the same frequency of augmented feedback, while allowing a comparison between bandwidth and no-bandwidth conditions.
In terms of KR frequency, those in the outside bandwidth condition received quantitative KR on 25 percent of the sixty practice trials; those in the inside condition received KR on 65 percent of the trials. The interesting feature of this difference is that the remaining trials for both groups were implicitly qualitative KR trials, because when they received no KR, the participants knew that their performance was "good" or "not good." The retention test performance results showed that the two bandwidth conditions did not differ, but both yielded better learning than the no-bandwidth conditions. These results show that establishing performance bandwidths as the basis for providing quantitative KR yields an interplay between quantitative and qualitative KR that facilitates skill learning.
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A practical issue concerning the use of the bandwidth technique relates to the instructions provided about the bandwidth procedure. This issue is relevant because when the learners receive no augmented feedback about their performance, the implicit message is that it was "correct." There is an instruction-related question here: Is it important that the learner explicitly be told this information, or will the learner implicitly learn this information during practice? According to the results of an experiment by Butler, Reeve, and Fischman (1996), the bandwidth technique leads to better learning when the participants know in advance that not receiving KR means they are essentially "correct."
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Erroneous Augmented Feedback
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One of the ways augmented feedback hinders learning is by providing people with erroneous information. While this statement may seem unnecessary because it makes such common sense, the statement gains importance when it is considered in the context of practicing a skill that can be learned without augmented feedback. In this skill learning situation, augmented feedback is redundant with the information available from task-intrinsic feedback. As a result, most people would expect that to provide augmented feedback would be a waste of time because it would not influence the learner. But research evidence shows that this is not the case, because even when augmented feedback is redundant information, beginners will use it rather than ignore it.
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The first evidence of this type of effect was reported by Buekers, Magill, and Hall (1992). Participants practiced an anticipation timing task similar to the one used by Magill, Chamberlin, and Hall (1991), which was described earlier in this chapter as a task for which KR is not needed to learn the task. In the Buekers et al. experiment, three of four groups received KR after every trial. The KR was displayed on a computer monitor and indicated to the participants the direction and amount of their timing error. For one of these groups, KR was always correct. But for another group, KR was always erroneous by indicating that performance on a trial was 100 msec later than it actually was. The third KR group received correct KR for the first fifty trials, but then received the erroneous KR for the last twenty-five trials. A fourth group did not receive KR during practice.
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The results (figure 15.3) showed two important findings. First, the correct-KR and the no-KR groups did not differ during the practice or the retention trials, which confirmed previous findings that augmented feedback is not needed to learn this skill. Second, the erroneous KR information led participants to learn to perform according to the KR rather than according to the task-intrinsic feedback. This latter result suggested that the participants used KR, even though it was erroneous information. Even more impressive was that the erroneous KR influenced the group that had received correct KR for fifty trials and then was switched to the erroneous KR. After the switch, this group began to perform similarly to the group that had received the incorrect KR for all the practice trials. In addition, the erroneous information not only influenced performance when it was available but also influenced retention performance one day and one week later when no KR was available. A subsequent experiment (McNevin, Magill, & Buekers, 1994) demonstrated that the erroneous KR also influenced performance on a no-KR transfer test in which participants were required to respond to a faster or slower speed than they practiced.
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The preceding demonstrations of erroneous KR effects were based on laboratory tasks, but similar results have been shown for sports skills. For example, an experiment by Ford, Hodges, and Williams (2007) had skilled soccer players kicking a ball to a target, which required that the ball achieve a specific height during its flight. One group of players received erroneous KR about the height of the ball's flight during each kick by observing a prerecorded video clip of a kicked ball that reached a height that was different from their own. Results showed that the players eventually based the height of their kicks on the erroneous video feedback rather than on their own sensory feedback. Erroneous augmented feedback has also been used in clinical settings to treat people with chronic pain conditions that are thought to result from distorted representations of the painful body part. For example, presenting osteoarthritis patients with resized images of their arthritic body part has been shown to change the patients' distorted perception of the size of the body part and reduce their pain (e.g., Gilpin, Moseley, Stanton, & Newport, 2015).
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Why would erroneous KR affect learning a skill for which KR is redundant information? The most likely reason appears to be that when people perform skills, they rely on augmented feedback to help them deal with their uncertainty about what the task-intrinsic feedback is telling them. For the anticipation timing and soccer kicking tasks referred to earlier, the uncertainty may exist because the visual task-intrinsic feedback is difficult to consciously observe, interpret, and use. Evidence for an uncertainty-based explanation has been demonstrated in experiments by Buekers, Magill, and Sneyers (1994), and Buekers and Magill (1995).
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The important message for practitioners here is that people, especially those who are in the early stage of skill learning, will use augmented feedback when it is available, whether it is correct or not. Because of their uncertainty about how to use or interpret task-intrinsic feedback, beginners rely on augmented feedback as a critical source of information on which to base how they will make corrections on future trials. As a result, instructors need to be certain that they provide correct augmented feedback.