# data[].attributes.body
I began taking tennis lessons when I was in third grade. I vividly remember my coach being on the other side of the net, feeding balls directly at me. However, I also remember the many struggles it took to finally make contact with the ball. After much repetition, not only did I continue making contact with the ball, but I also found ways to respond to the coach's feeds with my racquet and eventually hit the ball back to him over the net.

After learning about the stages of information processing, I now understand that I have been doing this numerous times throughout practice, even during my very first tennis lesson. In the first stage, stimulus identification, I must sense that a stimulus has occurred and what that stimulus is. For example, during this stage, I had to sense that my coach fed me the tennis ball, and have a feel for the balls' velocity, spin and height.

In the second stage, response selection, I must decide on an appropriate response to that specific stimulus. In this example, I had to decide which response to make in order to succeed at returning the ball. I needed to make a decision on how fast to turn my racquet, the angle at which my racquet needed to be, and which type of swing was needed (forehand or backhand).

In the third stage, response programming, I must prepare and initiate the response. In this specific situation, after I selected the appropriate response, I had to organize and send the commands down to my muscles to initiate the return. At the right time and once the ball was coming my way, I had to lower my racquet to the ground, move the racquet across my body once it made contact with the ball, and follow through over my shoulder.

It's important to note that each stage is independent, and that different types of balls (fed from my instructor) will result in differences in the stages of information processing.

In the image below, the player goes through the stages of information processing. First, he/she must know where the ball is coming from and how fast it is moving (the stimulus), then be able to decide which return he/she wants to respond with (response selection), and initiate the response by sending the appropriate motor commands to his/her muscles (response programming).

# data[].attributes.headline
#2 Learning the Generalized Motor Program 

# data[].attributes.subject
#2 Learning the Generalized Motor Program 

# data[].attributes.body
I found myself getting better each time I practiced. Making contact with the ball became easier, and I found myself responding to the feeds much more quickly and accurately. Although the general instructions to swing the racquet and hit the ball were the same with each feed, there were unique features with each ball I was fed, and I had to react accordingly.

The reason I got better at performing the fundamentals of tennis is because I became more comfortable with the generalized motor program of the swing. A generalized motor program is a program that represents a class of movement patterns, rather than a specific movement pattern. In this case, the generalized motor program of a tennis swing is to lower the racquet, move the racquet across one's body, and then follow through over the player's shoulder. However, in order to be successful in game-like situations, each ball fed will be varied and the generalized motor program's features must change accordingly. Therefore, according to the Generalized Motor Program Theory, the generalized motor program for swinging a racquet can be customized for each unique ball that is fed.

In the image below, the player is using an example of a customized form of the generalized motor program for swinging a tennis racquet. Because the ball is on the left side of his body and he is right-handed, he must perform a backhand in order to make contact with the ball. This is an example of a customized form of a generalized motor program for swinging. He is still lowering his racquet, moving the racquet across his body, and following through over his shoulder. However, he is doing this all on the opposite side of his body than he normally would, and with two hands.

# data[].attributes.headline
#3 Understanding My Instructor's Feedback 

# data[].attributes.subject
#3 Understanding My Instructor's Feedback 

# data[].attributes.body
Not only did my understanding of the generalized motor program for swinging improve, but so did my overall tennis game. This improvement can be attributed to the feedback I received from my instructor.

I was often attentive to my intrinsic feedback, or feedback that is naturally given from my sensory receptors, when playing tennis. I paid attention to my body's differing positions when serving the ball in and out of bounds. Not only did I often receive intrinsic feedback, but also augmented feedback. Augmented feedback is information that comes from an external source (my instructor) that supplements intrinsic feedback. Augmented feedback is divided into two forms: knowledge of results (KR) and knowledge of performance (KP). My tennis instructor used both, and described my performance outcomes (KR), as well as the movement characteristics that led to those outcomes (KP).

All of this feedback occurred after I was done performing a specific swing or serve. This is important because, after leaning more about feedback guidelines, I learned that feedback should always be given once the performer has finished the skill. This causes the learner to be able to direct his/her attention to the intrinsic feedback when performing the skill, observing the results, and then additionally listening to the feedback from the instructor after the skill has been performed.

The image below is of an instructor giving augmented feedback to his player. More specifically, he is giving feedback on knowledge of performance in the verbal form. This is the most common method of providing augmented feedback, but it must be noted that the type of words used when giving verbal KP is important. The players have a very limited attention capacity when learning a new skill, and as an instructor, it's important to keep that in mind.

# data[].attributes.headline
#4 Learning the Speed-Accuracy Trade-Off

# data[].attributes.subject
#4 Learning the Speed-Accuracy Trade-Off

# data[].attributes.body
As I grew older and continued working on having a stronger, faster, and more sophisticated tennis game, I came to understand the many different ways one can hit a ball back to his/her opponent. Tennis requires much skill in that, in order to get the ball where you want it to land, you must be able to hit the ball with a certain speed, and turn your racquet at a specific angle to get a specific spin.

I struggled with this concept a lot. I often found myself hitting the ball too hard and turning my racquet too fast, only to find the ball stuck in the net. This is a common cause of frustration among many players. Oftentimes, especially during a fast-paced, thrilling match, players get too caught up in the energy of the game and forget to take their time on easy returns. For example, when a player gets an easy return from a lob-shot made by the opponent, he/she returns that ball with so much spin and speed that the player is unable to hit it back. However, if a player does this too quickly, the ball often ends up in the net or out of bounds.

After learning about Fitt's Law, I can understand how the concept applies to this situation. During situations that require both speed and accuracy, there is an important trade-off that players must understand. Fitt's Law describes an inverse relationship between the difficulty of the movement and the speed at which the movement can be performed. In this example, when players move too quickly, their accuracy is compromised and end up losing the point by hitting the ball out of bounds or in the net. So, in order to remain accurate and ensure that the ball stays in bounds, players must slow down the movements with which they make their returns.

In the image below, Rodger Federer fully understands what it takes to return the ball. As you can see, he is moving his arm at a specific speed and angle to get the ball exactly where he wants it to go. However, it is easier and more automatic for him to make more accurate/complex shots, so he can spin the ball at a much faster speed.

# data[].attributes.body
I was in high school when I began playing tennis competitively. My coach assigned me with the position of #1 singles, which means that I often played against very experienced and skilled opponents. During my first few matches, I struggled returning serves and shots that my opponent threw my way. Oftentimes, when I was finally able to return a fast serve, the opponent would send back a return that was much too fast and at too sharp of an angle for me to return. However, through continued practice, I understood what it took to be able to do this, and this ability is what led me to win matches.

I can easily relate this specific situation to the concept of single-channel (or serial) processing. The Psychological Refractory Period phenomenon attempts to explain the delay in responding to the second of two closely-spaced stimuli, a situation that often occurs in human performance. In situations where two stimuli occur unexpectedly close together in time, there is a temporary bottleneck in the response-selection stage, where the first action must be organized and initiated before the second can, which results in a time delay.

When I was struggling to return hits that would quickly come back to me, I was experiencing the Psychological Refractory Period. The spin and angle of the opponent's racquet would send an initial stimulus in which I had to guess where the ball would go and respond appropriately. Shortly thereafter, the ball would quickly come on my side of the net, the second stimulus, but would be at a completely different angle than expected. I had to then respond by sending an entirely different motor command to my muscles, often missing the ball and losing the point.

The reason for this is because the two stimuli occurred too close in time - I was responding to the first stimulus, recognized the second stimulus, but because only one action can be initiated and organized at a time, there was a delay and the ball would be gone by the time I could reach it.

In the image below, the player struggled to make contact with the ball, most likely because he expected the ball to go to a specific location, but it ended up landing at a shorter distance. By the time he realized this and was able to initiate a second response, he was too slow.

# data[].attributes.body
When my older sister began watching me compete in tennis, she was interested in trying the sport. I often took her out to the public tennis courts and taught her the basic facts and rules about the game, as well as the fundamentals of physically playing.

What I found, while teaching my younger sister, was that it was much easier to verbally describe the basic rules of the game than it was verbally instructing her to swing a racquet. I understood the reason for this more clearly after learning about the differences between procedural and declarative knowledge.

Declarative knowledge is knowledge of facts that can be verbally stated, whereas procedural knowledge is knowledge of instructions for the performance of an activity. So, in this situation, when I was describing to my sister the rules of tennis, I was expressing declarative memory. The reason why talking about the rules of tennis was much easier than talking about the body mechanics of the game is because the declarative memory system contains the knowledge of which we are consciously aware. In contrast, procedural memory contains the memories underlying skills in the three domains of skilled behavior: cognitive, perceptual, and motor. It is often non-conscious and automatic.

In the image below, the tennis instructor is teaching the young boy to swing his racquet and make contact with the ball. One of the reasons he has the child holding the racquet but is actually moving the racquet with this own hand is because it allows him to not only verbally express how to swing the racquet, but also physically help the child feel the swinging motion. It is much harder to verbally express procedural knowledge, so by adding verbal cues while physically showing the motions of the swing, the child is much more able to understand.

# data[].attributes.body
Because I found it difficult to verbally express what I was trying to get my sister to physically do, I often demonstrated the skills. I wanted my sister to receive information and tips that would be most helpful to her. Since she was a novice learner and learning new coordination patterns at the time, demonstration was the most effective means of of getting my point across. However, if she was a learner that had already mastered the coordination patterns I was trying to teach, this would not be an effective form of instruction.

I was able to effectively instruct my sister on how to serve in tennis because I had previous knowledge of the skill and knew how to serve properly. However, I didn't always serve correctly, and I hit the ball either in the net or out of bounds. Surprisingly, learning from both a skilled and unskilled demonstrator has its benefits. Since my sister was able to observe my mistakes, she was also able to understand the incorrect steps I took that caused my ball to go out of bounds. What added strength to my incorrect demonstration is that, with my intrinsic feedback, I was able to tell her the incorrect positioning of my body that caused the mistake.

The image below represents a possible mistake when demonstrating a tennis serve. It is of benefit to the learner if he/she observes this serve because he/she is able to understand that the demonstrator took his eyes off the ball too early, swung too early, and lifted up his back foot. Observing this allows the learner to understand that those steps are incorrect, and he/she should not imitate them. However, it would be more beneficial for the demonstrator to describe this to the learner, for he/she may not understand exactly what went wrong.

# data[].attributes.body
With much practice, my sister got better at playing tennis and soon, we were playing together as if we were in a real match. Although it took years of practice, we improved the perceptual motor abilities needed to succeed in tennis.

Some perceptual motor abilities needed to play tennis include:
1. Multi-limb coordination, or the ability to coordinate the movement of multiple limbs at the same time,
2. Control precision, or the ability to make highly-controlled movement adjustments to visual stimuli when large muscle groups are involved,
3. Reaction time, or ability to respond rapidly to a signal when it appears,
4. Rate control, or the ability to produce continuous anticipatory movement adjustments in response to changes in the speed of a moving object (the tennis ball), and
5. Aiming, or the ability to produce accurate hand movements to targets under speeded conditions.

Tennis involves the coordination of both arms and legs, and highly-controlled movement adjustments with those arms and legs are necessary to be able to reach the moving tennis ball. Furthermore, because the ball moves so quickly, it is necessary to be able to rapidly respond to its rapidly changing location. Having the ability of a quick reaction time requires the ability of rate control. Because the speed of the tennis ball changes during a point, players must be able to make adjustments with their own movements in response to the ball's location. Finally, successful tennis players must be able to have accurate, fast hand movements to keep the ball in bounds and aim it where they want it to go.

In the image below, Serena Williams is exhibiting all five of the perceptual motor abilities that were just described. Tennis involves both coordination and accuracy under speeded conditions, which is what many of these perceptual motor abilities require.