A homogeneous class is one in which students are similarly grouped, i.e. Ethnicity or skill level. Example 1 (ethnicity) - When I taught English on the U.S./Mexico border, my classes were homogeneous because all my students were Mexican. Example 2 (skill level) - On the first night, all new students are put in the same room for orientation and placement testing, but then they are divided into more homogeneous classes according to their writing ability.
