A thesaurus is most helpful for students who must find the correct pronunciation for a difficult new word.
need to find multiple definitions for one word.
would like to keep their writing from becoming repetitive.
are looking for multiple forms of one word.

Although alice walker published a number of essays, poetry collections, and stories during the 1970s, her third novel, the color purple, ) which was published in 1982, brought her the widest acclaim in that it won both the national book award as well as the pulitzer prize (b) published in 1982, bringing her the widest acclaim by winning both the national book award and the pulitzer prize (c) published in 1982, brought her the widest acclaim, winning both the national book award and the pulitzer prize (d) was published in 1982 and which, winning both the national book award and the pulitzer prize, brought her the widest acclaim (e) was published in 1982, winning both the national book award as well as the pulitzer prize, and bringing her the widest acclaim