premise: The Left Switch<br>Parker had been trying to learn guitar. No matter what he did he couldn't seem to get it very well. Then he realized that he was playing right handed. Parker was left handed so he decided to try switching. To his delight this helped him to play much better.
hypothesis: Parker does everything with his left hand
reason: It says he is left-handed, that does not mean he dominantly uses his left hand for all activities.