Would you say that the diction is simple and straight forward? The text is pretty easy to read and comprend. Steinbeck's style would be described as what?

http://college.hmco.com/english/heath/syllabuild/iguide/steinbec.html
Read especially the section subtitled Significant Form, Style ...

http://web.csustan.edu/english/reuben/pal/append/steinbeck_bio_s99.html
Read carefully.

=)