Rates of Skill aquisition affects the performance because it determines how well the athlete performs at a particular point in time. This in turn can affect motivation. Think about it:
- Linear - The more you learn, and the more effort you put in, the sooner and better the skill is performed. Someone who learns on a linear curve is likely to maintain motivation and hence performance as they are getting results from the effort they put in.
- Negatively accelerated curve - Early on there are a lot of gains, which rise exponentially with the amount of time and practise put in. This is positive reinforcement and aids the athlete to keep training and practising. Later on, there is a plateu - which could prove detrimental in the athletes motivation.
- Positively accelerated curve - Early on there is very little result from the practise, as the skill is difficult and time consuming to master. This can have adverse affects on motivation because an athlete can be putting in a lot of time and evergy but getting very little out in return. Later on there are vast improvements that signify where the skill has been learnt and is (finally) working. This can affect motivation as an athlete might not necessarily be "putting in the work" at this stage - which can give them reinforcement for not training hard.
-S shaped curve - This one has some rapid gains followed by periods of very little or no gain in performance followed again by periods of rapid gain. The graph signifies particuarly hard skills to learn - which are broken down into different parts. For example Freestyle swimming - you teach the kicking, the underwater pull, the overarms, the side breathing, bilateral breathing etc. Each skill in itself can be learnt and put together at the end to make up the whole freestyle stroke. MOtivation can be affected as these skills are frustrating to learn and often it will feel like taking two steps foreward one step back.
There you go - a summary of the effects that each of these has directly on performance and indirectly on performance (through its effect on motivation).