Fourth Graders Composing Scientific Explanations About the Effects of Pollutants

Abstract

Explanation as a genre may support children's reasoning and understanding particularly effectively. In this study, 20 fourth graders were given the task of explaining the effects of a pollutant on an ecosystem to third graders. Before writing, they completed a commercially developed science unit, instruction in reading and writing an explanation, and text reading. An analysis of their writings revealed that all children used rhetorical devices to connect with third-grade readers. Sixteen children synthesized text content with personal experiences to compose subexplanations that reported information, gave examples, and presented scenarios and that were logically ordered to enhance reader understanding. Nine of these children explicitly used the scientific model to explain phenomena. Outcomes suggested that writing explanations supported children's reasoning about and understanding of an important scientific model.

Planning text structure as a way to improve students' writing from sources in the compare–contrast genre

“…This possibility has also been noted by Boscolo and Borghetto (2002) and Chambliss et al (2003). It would be particularly interesting to examine this possibility with older students, who could compare and contrast complex subjects, such as authors, texts, or theories.…”

“…Students were asked to work in pairs (as suggested by Stead, 2002) to rate these samples, and the ratings were discussed as a class. Teachers modeled how to create the planning in a table (IAPN, which is presented in section 2.4.1), and how to use it to write a text (in keeping with Bereiter & Scardamalia, 1987;Chambliss et al, 2003;Englert et al, 1991;Graham & Harris, 1997;Pressley, 2003;Pressley et al, 1995;Wong, 2000;Zimmerman & Risemberg, 1997). Students also had the opportunity to plan and write independently (as suggested by Harris & Graham, 1996).…”

“…Students were provided with examples of good and poor compareecontrast texts (in keeping with Chambliss, Christenson, & Parker, 2003;Hammann & Stevens, 2003;Hidi, Berndorff, & Ainley, 2002;Pressley et al, 1995;Risemberg, 1996). The good texts addressed both topics/objects equally and were written with the macro-aspect structure, while poor texts either addressed one topic more heavily than the other, or contained equal, but disorganized information about the topics.…”

Characterizing High School Students’ Written Explanations in Biology Laboratories

“…Therefore, codes were assigned for the function they serve in the text or the meaning or the idea they convey in the text. Similar strategies were previously used by researchers to analyze student writings (Chambliss et al 2003;Keys 1999). Some code units were, evidence, cause, effect, elaboration, inference and hypothesis.…”

“…There may be a mismatch between the cognitive work required for students to succeed in the biology curriculum and the types of reasoning with which adolescents readily engage. Indeed more recent research showed that scaffolding students' scientific explanations through various ways, such as explicit teaching of explanatory genre (Chambliss et al 2003), or through written explicit guidance in laboratory worksheets that identifies explanatory elements (e.g. claims, evidence, McNeill et al 2006) or through computer software that provides explanation guides (Sandoval 2003), results in better student explanations.…”