'An investigation into the significance of Hull's Inhibition Theory when tested against the performance of netball players of good ability'.

AS and A Level Physical Education (Sport & Coaching)

Robin Wright Msc

Rec 282/182

Sports Psychology Outdoor Recreation IV and Golf Studies IV

Assignment

022063614

Aaron Noremberg

‘An investigation into the significance of Hull’s Inhibition Theory when tested against the performance of netball players of good ability’

Abstract:

Throughout the course o f the investigation, the significance of Clark Hull inhibition theory on the shooting performance of netball players was examined. The aim was to introduce rest periods of different lengths into group of 100 shots, and examine and analyse the effects of these rest periods on the participants to see what effect they would have on combating the inhibition in the players shooting. A wide range of research into Inverted U theories, drive theories, inhibition, shooting mechanics and the psychological and physical reasons behind the diminishments in performance was conducted. The experiment was carried on using 5 players of similar age (18 – 20) and ability (university netball team), and all attempted their groups of shots under identical circumstances:-

100 shots no break

100 shots, after every 20 shots a 2-minute break

100 shots, after every 20 shots a 5-minute break

100 shots, after every 20 shots a 10-minute break

Results were recorded on prepared tables, then transferred the information onto graphs where they could be easily compared and contrasted. From the results it was discovered that whilst the 2 minute break resulted in the highest average shooting success rate, the 10 minute break proved best at combating inhibition, although large breaks also had the expected detrimental effects on shooting performance.

Using the statistical data, it has been proved of my hypothesises is that the H1 hypothesis will be accepted, inhibition will clearly represent by the Inverted U theory over 100 shots, when no break is allowed. Whilst the H0 hypothesis, there will be no difference in shooting performance over 100 shots when no break is allowed was rejected (null).

An investigation into the significance of Hull’s Inhibition theory, when tested against the performance of netball players of good ability.

Hypothesis H1: Distributed practice will be significantly more effective at combating inhibition than massed practice.

Null hypothesis H0: Distributed practice will be not significantly be more successful than massed practice at combating inhibition.

Introduction:

Clark Hull dive theories explain the effects of factors such as incentive drive, need, inhibition and reinforcement (conditioning) on the performance of sport players. Clark Hull highly mathematical approach to the subject, meant that all his theories could be clearly demonstrated using the ‘Inverted U hypothesis, which predicts a curvilinear relationship between the influential variable, (example drive) and the subjects performance:

Inverted U Theory: Fig 1

The Inverted theory perceived, far more support than the original idea that as ‘drive factors’ increase in intensity, so will performance. This original idea would have meant that the more worked up (aroused) a player became, or most that person attempted, the better the player would perform, with no limiting factors. Clark Hull believed that arousal reached a certain point, then it would impede performance. Oxendine, an American psychologist, believed that arousal would have detrimental effects in sports that relied upon complex motor co-ordination and high levels of concentration such as snooker, darts and golf (including discrete skills), but it would improve performance in gross motor skilled sports such as boxing, wrestling and weight lifting (Advanced studies in physical education and sport, Nelson)

The ‘Inverted U’ theories can be used to reflect upon need, reinforcement, incentive, drive and also inhibition.

Clark Hull theories of inhibition states that despite repeated practice improving success when a person repeats the homogenous movement over and over again, they gradually build up an ‘inhibition’ which as a detrimental effect on the result of the final skill/movement. A good example of this theory would be a basketball player repeatedly taking the same shot form the free throw line a 100 times. Clark Hull believed that of the shot would its greatest at the 50th attempt, and from that point onwards, performance would decrease(less shots would be accurate). Clark Hull also stated that the introduction of a rest period would reduce the effects of inhibition.

Drive and Inverted U Theory: Fig 2

The one major criticism of Clark Hull’s work that he relied entirely on quantitative data (rather than qualitative data). It is important to take into account qualitative factors as well as quantitative factors when carrying out the investigation, such as personality traits, which can only be seen through the use of qualitative data (interviews, case studies, questionnaires etc)

The objective of this investigation is to examine the effects of inhibitions on netball players when 100 set shots, and the subsequent effects of introducing rest periods to combat inhibition’s detrimental effect on performance.

What causes inhibition? :

Physical causes: Tiredness/fatigue- The repeated execution of the movements involved in shooting will lead to fatigue/tiredness in the muscles, caused by the onset of blood lactate accumulation (OBLA), at point where the body can no longer produce enough energy to complete the movements by respiring aerobically, and produce lactic acid to provide energy an aerobically. OBLA is the point at which the lactic acid concentration in the blood rises above millimoles per hundred (mmol)

OBLA, and so fatigue, occurs later in athletes who have higher aerobic threshold and general regarded as fitter/healthier. Increased tolerance to lactic acid build up in the muscles can be achieved through overload training, which causes an increase an ATP (Adenosine-tri-phosphate) and CP (Creatine phosphate) stores, increased glycogen stores, increased enzyme production also hypertrophy of the muscles

An athlete aerobic threshold can be raised through endurance training which causes cardiac hypertrophy, increased stroke volume, a lower resting heart rate, and therefore also a greater range and maximum cardiac output, allowing more 02 (oxygen) to reach the muscles.

Fatigue is such an important factor in shooting success because the speed and the angle of release of the shot are the most important governing factors. It has been ascertained that an angle of release between 49 degrees and 55 degrees will provide the shooter with a greater likelihood of success, with the optimum use of speed and height resulting in angle of entry around 60 degrees (the best angle of entry is 90 degrees, but it relies on near impossible combination of strength, speed and angle of release). (Bunn 1972, the scientific principles of coaching, Prentice hall)

Psychological causes: Motivation has many definitions, the wish, desire, drive impulse to participate in/perform well at a sport/goal directed activity. The desire is associated with the expectation that positive outcome will ensure. The dive to achieve will to win/aspirations. The direction of behaviour/level of arousal. The reasons why people do what they do. The energised state which prepares us to act. Motivation is a strong factor on how well the participant will perform.

The onset of boredom will vary depending on the personality traits of the netball player, specifically the motivation/achievement need aspects. One shooter may feel the ...

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The onset of boredom will vary depending on the personality traits of the netball player, specifically the motivation/achievement need aspects. One shooter may feel the need to achieve just for the satisfaction she may receive from scoring highly from her 100 shots where as another may have no motivation to perform at all, and just view the shots as a task to be undertaken. Clark Hull, inhibition theory tests eliminated factors such as motivation, and all external factors effecting results will be eliminated.

Boredom is not contrary to popular belief, a result of having nothing to do. It’s very hard to come up with a situation where a person options are so limited that he or she literally can do nothing. Attempting to impersonate an emu at a funeral may be inappropriate, but that doesn’t mean that it isn’t an option. Boredom stem from the situation where none of the possible things that a person can do, realistically appeal to person in question. This renders the person inactive, and generally unhappy. Thus boredom is the result of having nothing to do that one likes. Also, it is requires that the person be a relative state of rest, and under low level of pressure (Vincent Joseph Shuta 1993, Gross psychology for mind and behaviour)

The process of repeating the same shot 100 times, with no external incentive, is likely to lead to a diminishment in shooting standards at some stage in the experiment, where the test subject may not take the same care over her shot as she did at the outset, as the execution of the shot is a complex movement (as explained later)., then any slight change in position, shooting angle or shooting power could lead to a dramatic change in shooting results.

Personality, characteristics which lead people when placed in similar circumstances to react/behave in different ways. Personality is important in the experiment, as the test subjects will have different personalities, which in turn will have different characteristics. This could effect the outcome of the results, it is important to know what type of characteristics that will give the best results The psychology theory that has dominated the field of personality, in sport players and athletes, is the ‘trait theory’. The theory is based that our personality is made up of a finite number of characteristics or traits (continuous quality that individuals possess in different amounts). Thomas Tutko and Bruce Ogilvie argue that certain characteristics marked out successful sports people they are: aggression, coach ability, conscientiousness, determination, drive, emotional control, guilt proneness, leadership, mental toughness, self confidence and trust. If the participants don’t have any of these traits, it would inhibit their performance, most likely they will have some of these characteristics, but it can be said more the characteristics, more chance of being successful.

Attitude is a subjective evaluation of someone or something. In sport there are positive or negative attitudes. Factors in which constitute to a positive attitude, are that the person believes what they are doing is beneficial to themselves, enjoyment of the activity (netball) and having regular participation in the activity. Some factors that contribute to negative attitude to sport are the perception that you have low ability, fear of failure and previous poor performance (learned helplessness). In the experiment the players are of good ability, so that should not affect the performance, but if the participants start feeling that too much pressure, and feeling the fear of failure, so there should no pressure put on the participants. All the players have been playing for over 3 years, and play regularly which introduces positive attitude to netball, which in turn is that they will have a positive attitude to activity placed on them in this experiment (100 shots).

Goal setting, the lack of goal setting would inhibit the performance. It is important that each participant sets a goal, the goal would be for example in this experiment would be to get the ball in the net. The system of stating/specifying long-term performance targets and the short-term objectives/methods to achieve these. The purpose of goal setting is to provide a participant focus, guide future actions to improve, maintain good levels of performance and to motivate. Goals should be specific, measurable, attainable, re adjustable, time scaled, exciting and rewarding. The importance of goal setting is that with out accomplishment of the goal, motivation would become highly diminished. The rewards of achieving the goal also improve motivation.

Basic Prediction: Fig 4

Taking Into Account Physiological and Psychological Factors: Fig 5

Shooting Method/Mechanics :

The set shot in basketball is regarded as the foundations upon the netball shooting techniques are developed.

For the execution of the netball shot on the opposite side as the shooting hand, and is placed a short distance further in front than the other foot, and is pointed in the direction of the basket. The back foot is positioned slightly to the side and pointing forwards and outwards at approximately at 45 degrees angle. This is because in netball shooting the need for accuracy outweighs the need to develop high velocity upon release. The netball shot stance means forces exerted on the ball act almost exclusively upon its direction.

For the right hand shooter, the ball is held at just above chest height, with the left arm straightened and pointing in the direction of the basket. The right hand is directly behind and somewhat below, with palm forward and finger pointing up. The right hand then lifts the ball past the face in the direction of the basket, with the extension of the right arm’s elbow and a flexion of the right wrist and fingers. The shooter stance may vary during the taking of the shot, as the shooter might need to adjust their centre of gravity.

At the moment of release the shooter eye’s, right and left shoulder, both elbows, both wrists should be inline of the basic.

Netball Shot: Fig 3

Aims:

In this experiment the aim is to investigate whether the use of significant rest periods combat inhibition in netball shooting, by examining the shooting success rates of five players under the following circumstances:- ( A pilot/mock study was done before this experiment to test if these requirements are useful to test the combat the inhibition, results show that the variables used are the best to show the results of this study- results of this pilot/mock are in the appendices)

1st February, 13:00, all participants 100 shots no break (all participants separated)

2nd February, 13:00, all participants 5 groups of 20 shots with 2 minute breaks (all participants separated)

3rd February, 13:00, all participants 5 groups of 20 shots with 5 minute breaks (all participants separated)

4th February, 13:00, all participants 5 groups of 20 shots with 10 minute break (all participants separated)

Variables:

Variables that could affect the study: -

In order to test Clark Hulls inhibition theory, it is important to eliminate all other factors which he believed would effect performance,( incentive, drive/arousal, need and reinforcement). This can be done by making it clear to test subjects that the experiment is not a test or competition, and has no prizes (rewards). Results would be confidential, with no disclosure of names (to comply with all the ethical guidelines)

The timing of the experiment could affect performance. The experiment will be carried at 13:00, and therefore will be no lunch, this in turn will lead to know biological differences in performance of each subject.( diet, existing fatigue if the experiment was at the end of the day, tense muscles if the experiment was at the start of day)

Test subjects short term diets will effect their performance, because of this, the subjects will be requested to relinquish having lunch, and just have breakfast that would consist of, toast or cereal, both of which are high in carbohydrates. A light carbohydrate snack should be consumed during a break between 11:00 and 11:15. An isotonic drink should be taken at 12:00 an hour before the activity. To keep this variable constant, all the test subjects must stick the same short-term diet.

Better quality equipment could benefit any one shooter. In order to eliminate this, each performer will wear their university strip, and the basket that has been kindly given by the university will be used. The same ball will be used for all participants; no one should gain any advantage.

Temperature and lighting could have positive or negative effects on performance, so I have decided to do the testing in the university hall, where I can control the variables of lighting and temperature, all the same variables will be the same on all days, when activities take place.

All participants are non-smokers, and it the participants have been requested stay of places where smoking is taken place, from two days before the start of testing and all the way through testing. Alcohol will also be requested not to have any, for the same amount of time as the smoking restriction.

Equipment:

Netball basket a line which is 1 metre away from the basket, the netball basket will be situated at 15 feet high.

An official match ball (provided by the university) which all the participants are accustomed to

Proper recording equipment, laptop will be used, and back up for possible laptop breakdown, recording sheets, paper and 3 pens

Method:

Method of investigation, shooting ability will be determined by looking at the standard at which the subject has played and also by recording the players basic shooting score out of 10. all the university players will attempt 10 shots, and scores will be totalled, the 5 participants with the top 5 scores will be chosen to take part in the experiment. All participants taken place achieved over 5 baskets.

Method of testing day:-

Each selected players will attempt 100 shots from the 1 metre line with no break or rest allowed and no change in technique (see shooting mechanics).

Results are recorded on both laptop and record sheets, using 1 to represent a basket, and 0 as a miss. A percentage score for every is worked out and then plotted on an Inverted U graph

The next scheduled activity, the process is repeated again, 100 shots will be taken with a 2 minute break between every 20 shots, no change in shooting technique.

Results are recorded on both laptop and record sheets, using 1 to represent a basket, and 0 as a miss. A percentage score for every is worked out and then plotted on an Inverted U graph

The next scheduled activity, the process is repeated again, 100 shots will be taken with a 5 minute break between every 20 shots, no change in shooting technique

Results are recorded on both laptop and record sheets, using 1 to represent a basket, and 0 as a miss. A percentage score for every is worked out and then plotted on an Inverted U graph

The next scheduled activity, the process is repeated again, 100 shots will be taken with a 10 minute break between every 20 shots, no change in shooting technique.

After each shot I would retrieve the ball and pass the ball back to the shooter.

Results:

Detailed results are in the appendices.

Statistical analysis: In order to check the validity of the investigation, s statistical analysis was used. It was carried out on the results for 100 shots, no break in order to see if inhibition was present. Unfortunately, because the investigation was not testing general drops or improvements in performance, the paired sample t-test had to be carried out twice, the first time to see if shooting had improved until the 50th shot and the second to see if there was any significant statistical difference between the first 20 shots and the last 20 shots. If the second test not meet the ‘t crit’ and the first did, then the original H1 hypothesis would be proved. If the second test did not meet the ‘t crit’ or the first failed to, the H0 hypothesis would have to be accepted.

H1 hypothesis: Distributed practice will be significantly more effective at combating inhibition than massed practice

H0 hypothesis: Distributed practice will be not significantly be more successful than massed practice at combating inhibition

T crit between the first 20 shots and final 100 = 0.360667853

Rejected (with reference to Table A)

T crit between the middle 50 shots and the final 100 = 0.20841613337

Accepted (with reference to Table B)

There has to be 97% significance P>0.03

H1 Accepted.

Table A

Table B

Analysis of Results:

In order to thoroughly analyse my results, graphs are used to examine each subjects results individually, and then they will compared and contrasted to each other (these can be seen in the appendices).

Round up of results:

Participant 1: 100 shots, no rest; shooting results followed basic ‘inverted u’ hypothesis, with shooting improving until the 60th shot, from where the standard declined, before the last 10shots were it slightly rose again.

Every 20 shots, 2 min break; followed almost identically the pattern of the ‘no rest’ test, although the success rate was slightly lower.

Every 20 shots, 5 min break; showed slight evidence of inhibition, but results was too general to draw any significant conclusions. The rise and fall were slight enough to have been caused by chance. The shooter was more successful with this break

Every 20 shots, 10 min break; a continual fluctuation in results, showing no evidence of inhibition or the ‘inverted u’ theory. This use of break brought about the shooter’s poorest results.

Participant 2: 100 shots, no break; clear evidence of inhibition. The only evidence of the ‘inverted u’ theory is between 10th and 20 shots, where the shooters results improve dramatically and then began to decline. The shooter’s average is second highest in the study.

Every 20 shots, 2 min break; despite an unusual high percentage success rate for the first 20 shots, both inhibition and ‘inverted u’ theory appear to be present. This rest period proved to be the shooter most successful.

Every 20 shots, 5 min break; clear evidence of inhibition but no evidence of the ‘inverted u’ hypothesis. The shooter 3rd most successful rest period.

Every 20 shots, 10 min break; no clear pattern to the results, although it is believed the 70 –8- group of shots are unusually high, and are an anomalous result. This long rest period provided the shooters lowest score.

Participant 3: 100 shots, no break; results clearly reflect the ‘inverted u’ hypothesis, giving the shooter her second highest success rate.

Every 20 shots, 2 min break; initially shows signs of ‘inverted u’ theory, but a rise in shooting success from the 80th shot onwards is unprecedented, and does not follow any of my hypothesis. It is an anomalous result. This short break provided the shooter with her highest success rate.

Every 20 shots, 5 min break; apparent inconsistent shooting at points in the series of shots made results irregular. However, the general trend is clearly of a continuous level of shooting with little evidence of inhibition.

Every 20 shots, 10 min break; showed slight evidence of inhibition but not the ‘inverted u’ hypothesis. A lack of shooting consistency, possibly caused by large periods of rest, makes the overall trend difficult to analyse with average [percentages causing graphs to be misleading.

Participant 4: 100 shots, no break; the subjects shooting clearly reflects the ‘inverted u’ hypothesis, with shooting success peaking early around the 3oth attempt, and then gradually declining. The subject achieves her highest score without the use of a break, which is rejecting my hypothesis.

Every 20 shots, 2 min break; after initial rise in shooting standard before the 20th shot, performance first drops, before rising again and then finally dropping again at the end. The 2 min break only about the shooters 3rd highest score.

Every 20 shots, 5 min break; the shooters performance appears to follow the ‘inverted u’ theory, until the 70th shot, which see a dramatic improvements in score rate which continues until the end of the test.

Every 20 shots, 10 min break; the subject shooting remains below average throughout, with increase in success only at the outset and conclusion of the experiment. This is the shooters lowest score.

Participant 5: 100 shots, no break; the result clearly follows the ‘inverted u’ theory, but with a far greater drop in performance after peak. The shooter gained her second best results

Every 20 shots, 2 min break; again, the results follow the ‘inverted u’ theory, but with the inhibition having a less effect on performance than it did when no result was taken. The shooter gained her best results.

Every 20 shots, 5 min break; the shooter results appear to follow opposite of the ‘inverted u’ theory. The shooter gained her worst results with this break

Every 20 shots, 10 min break; the shooters performance remained constant but below average.

Possible explanation of results:

Inverted U theory; shooting performance improves as the shooter finds her range and establishes a rhythm, then drops as fatigue and boredom sets in, the best example is participant 1, 100 shots no break.

‘U’ theory: the opposite of the ‘inverted u’ theory as seen in participant 5, when a 5 minute break after every 20 shots was used, this could possibly a reflection of the shooters lack of motivation or an incentive. If she concentrates only at the first and last 20 shots could lead to that result.

A rise in standards of shooter’s last 10 shots, seen in half of the shooting sequences, this is most likely to have caused by the shooters intrinsic desire to achieve a high score, and if she so close to a her goal, she will of if it is attainable in the last 10 shots.

A low standard of shooting over the initial 10 shots: most shooters scored well below the average over the first 10 shots, probably relating to either:-

Range finding
Cold muscles (no warm was allowed)
Lack of Rhythm

An inconsistent, below average performance: most often where the 5 and 10 minute breaks were introduced, and is most likely to have been caused by the same factors which affected the shooters at the beginning of all their shooting sequences. It is believed the constant disruptions will have an affect the shooters concentration.

Trends:

100 shots, no break; all but one participant results followed the basic ‘inverted u’ theory of inhibition, starting with a high success rate, ending with a low success rate. Despite the fact that inhibition was clearly evident in all cases, no break at all proved to be more successful than the longer breaks of 5 and 10 minutes, with shooting success rate of 60.0%.

2 min break very 20 shots: whilst not entirely eliminating inhibition, the 2 min break proved long enough for shooter to maintain a high standard of shooting success, whilst the break was not significant enough to cause a drop in standard associated from fresh or after a long break. The 2 min break proved to be the most successful of the all the four tests, with a shooting success rate of 63.2%.

5 min break every 20 shots; whilst entirely eliminating inhibition, the 5 min break was also seemed to disrupt the shooter concentration, resulting inconsistent shooting. Boredom may also have been a factor, as the shooter did nothing in rest periods. The 5min break resulted in only the third highest shooting success rate of the investigation with an average of 59.2%.

10 min break every 20 shots; whilst almost entirely eliminating inhibition, the 10 min break brought about many inconsistent results, and meant that shooting standards never got the opportunity to rise above the initial group of shots. The 10 min break meant that the shooters only achieved a success rate of 55.6%, 7.6% lower than average with 2 min break.

Discussion/Conclusion:

Limitations:

Throughout the experiment several limitations were encountered. Whilst carrying out the experiment, it was discovered that:

Where were large rest periods introduced, it was impossible for the participants to keep to my rigid timetable, dates had to be changed for not just social reasons but also with the amount of time it took for my parts of my experiment. Although any one sequence of 100 shots was never interrupted, this could lead to changes in external environmental factors, which were not original taken into account, also if a player was attempting 100 shots, and the session was running late, she may attempt to rush her shots, so she wouldn’t be late for lectures, appointments. Lowering the shooting success rates.

During the process of recording my results several limitations were discovered:

Any conclusion that could be drawn are limited to the small sample size that was used. By plotting shooting success rates every 10 shots, it was harder to see any obvious trends in results. As the netball players performance tended to fluctuate so much, and plotting results every 20 shots, although results appeared to be clear and easy to understand, the fact that all they showed was an average score over each o9f 20 shot group means that a degree of accuracy was lost from the plotted results, as an significant variation which occurred between the 1st and the 20th shot was merely averaged out. For this reason it was decided to plot the results for every 10 and 20 shots, but this resulted in the graphs appear too complex, and results being hard to distinguish.

Did my results reflect my original hypothesis?:

From the basic trend of my results, it can be concluded that the results did follow the basic hypothesis, as an introduction of a2 minute rest period, the performance increased by 2.8%, although extended rest periods of 5 and 10 minutes decreased performance by 4% and 10% respectively. It can therefore be concluded that whilst a small rest period is particularly successful at combating inhibition, large rest periods, whilst succeeding in combating inhibition also have a detrimental effect on performance.

Did my results support my research?:

Where each shooter attempted the 100 shots, in all but one case the pattern of their success rates followed that of the ‘inverted u’ theory and in the other case, inhibition was evident from the start.

The introduction of a 2 minute break combated inhibition to an extent, without lowering the players general performance. However, it was discovered that although the 5 and 10 minute breaks eliminated inhibition, the larger breaks also interrupted the players mental and physical; preparation enough to significantly lowering their shooting success levels. Over 100 shots, the best way to combat inhibition was a 2 minute rest, although it would seem that the more shots attempted, the greater the rest period would need to be.

Appraisal:

Possible steps to avoid the for mentioned variables:

Plan better timetable, allowing time for every player to complete her 100 shots within any 1 session, ensuring no player is rushing to meet any appointments, made prior to the experiment.

Increase sample size to provide a more comprehensive and conclusive results, at least 100 participants.

Research a clearer method of plotting my results on to graphs may be by plotting results every 10 shots, and then overlaying a line of best fit.

I would also like to use more statistical analysis, to further prove findings; this in turn would show clearer representation of what is found in the experiment.

In order to further my research, it would be possible to: -