Sentence:  `` Speed in painting a picture is valid only when it imparts spontaneity and crispness , but unless the artist has lots of <WSD>experience</WSD> so that he can control rapid execution , he would do well to take these first sketches and soberly reorder their design to achieve a unified composition . 
Meaning of the word marked with <WSD> tags:  the accumulation of knowledge or skill that results from direct participation in events or activities