Feedback is an extremely important tool used by coaches on a daily basis especially when it comes to skill acquisition but what do we really know about it and how should it be used for best results? As I stated in Overcoaching? many coaches (and some Governing Bodies) estimate their effectiveness on how often they interact with their athletes but just as explicit information is potentially harmful to an athlete can too much feedback or the wrong kind of feedback also a problem?
Once again the information presented on coaching courses is very sparse as regards this area so I will attempt to sum up the key components of feedback before looking at research that has been carried out and the practical implications arising from this.
Athletes receive feedback from two main sources:
- Intrinsic Feedback – sensory information from within their body
- Extrinsic Feedback – information from outside sources
Obviously coaching feedback falls into the Extrinsic Feedback category and there are two types of coaching feedback:
- Knowledge of Results (KR) – whether or not the goal was achieved
- Knowledge of Performance (KP) – information relating to the nature of the movement
As an example, after a sprint a 400m runner might simply be told their time and whether it was better or worse than the target time (KR) or that they were too tight in the upper body and not recovering their right leg properly (KP).
These two forms of feedback are both known as Augmented Feedback and Gabriele Wulf and Charles Shea claim that although both types of feedback serve different functions in the learning process, they both adhere to the same principles in the way they affect the learning of motor skills, thus they are not differentiated in research and are both known as either augmented feedback or just KR.
Feedback can be manipulated in several ways:
Studies have compared tasks where feedback is given on each trial (100% KR) versus reduced frequency of feedback such as 1 in 2 trials (50% KR) or 1 in 3 trials (33% KR). The main consideration here appears to be whether practice is constant or variable.
In constant practice (only practicing one task at a time) 100%KR is as effective as 50% KR but in variable practice (several similar tasks practiced in a session) reduced feedback (50% KR) is much more effective.
Feedback can be given concurrent with trials, immediately after a trial or delayed for a period of time after a trial.
Concurrent feedback given on 100% of trials has a powerful influence in improving performance during learning but causes severe decrements in execution of skills in retention or transfer tests post practice where feedback is absent. This suggests athletes become dependent on the feedback. By reducing frequency of concurrent feedback to 50% though this effect can be lessened but the performance during learning is reduced too.
Delaying feedback for a few seconds has been found to be more effective than giving it immediately after a trial. The theory is that the delay allows athletes to self evaluate the movement and estimate any errors made. As such anything that prevents learners from immediately evaluating their performance damages learning.
Bandwidth or Faded
Only providing feedback when a trial falls outside a window of acceptable performance – i.e. small errors are ignored so that as performance improves less feedback is given so that it “fades” away over time. Again this works best in variable rather than constant practice conditions.
Summary or Averages
Feedback is provided only after a set of trials (e.g. 5) have been completed. The length of summary (i.e. feedback after 5 trials or 15 trials) depends on the task. The simpler the task, the larger the summary should be (e.g. 15 trials) and the more complex the task the smaller the summary should be (e.g. 5 trials).
Internal or External Focus
This variable appears to be a real key to learning and performance.
- Internally focussed feedback relates to the positioning and movement of the learner’s body and limbs e.g. “Stand with your feet hip width apart and flex the knees, hips and ankles”. This internal focus causes the learner to consciously try and control their movement and results in a disruption to the movement.
- Externally focussed feedback directs the learner to achieve an overall outcome goal e.g. “Sit down as if there was a stool behind you”.
Shea and Wulf ran an experiment in which participants had to maintain balance on a stabilometer (balance platform). They were given identical feedback but it was presented in either an internally focussed or an externally focussed manner. One group was told the visual feedback they saw on a screen represented the movements of their feet (internal focus) and the other group that it represented the movement of the platform (external focus).
Learning was more effective in the externally focussed group and was retained even when there was a retention test with no concurrent feedback indicating that the external focus was more powerful than the dependence effect of concurrent feedback mentioned earlier. This fits in well with the proposed use of analogies from implicit learning to ensure stability of performance.
This blog by Chris Beardsley provides further information and examples of the benefits of an external focus from feedback and is well worth a read.
So in summary, when, how often and what you feedback to your athletes can have a large effect on their learning and performance. You should understand each of these factors and use the optimal variables according to the athletes you are coaching and sessions you are planning. You must also balance the desire to have an immediate impact on the quality of a session with the goal of improving long term performance.