Shahn, E, & Costello, R.K. (1994). Evidence and interpretation: Teachers' reflections on writing in an introductory science course. Unpublished manuscript.

The use of writing in an introductory science course intended primarily as a terminal course for non-science majors is considered in the context of a discussion of cognitive development. We suggest that, particularly where students are asked to justify their understanding by referring to concrete evidence, writing samples are a sensitive indicator of cognitive position. We demonstrate this with examples of four different types of writing used in our course: short answer exam questions, exam essays, take-home essays which may be revised, and informal journal writing. The information gained from writing assignments can be useful as feedback to an instructor regarding individual student's assumptions about what can be known in science and what form this knowledge takes, what individuals and the class as a whole are prepared to understand, or in what ways particular subject material is likely to be misunderstood. We conclude that these different probes can reveal different aspects of development, and that the use of any of them requires attentive reading by the instructor.