Sentence:  An examination of some forty catalogs of schools offering courses in interior design , for the most part schools accredited by membership in the National Association of Schools of Art , and a further `` on the spot '' inspection of a <WSD>number</WSD> of schools , show their courses adhere pretty closely to the recommendations . 
Meaning of the word marked with <WSD> tags:  the property possessed by a sum or total or indefinite quantity of units or individuals