What is the author's style in To Be a Slave by Julius Lester?

These stories of the American slaves are told in three ways: their own words, their own words edited by the white abolitionists in an effort to refute the notion that they were "inferior" to the whites, and in the author's summaries of his research of the thousands of stories. Some are eloquently stated; others are crude. This style allows the reader to get a sense of what it was like to be a slave.