Title: The Use of Evidence in Young Adolescents' Argumentation
Description: This study examined the various ways in which students who participated in a two-year-long evidence-focused argument curriculum use evidence when engaging in argumentation. The experimental group was compared to groups who received either no such argument curriculum, or one year of an argument curriculum without focus on evidence. A total of 93 students participated in the study; at the end of the two-year period, all students were assessed on various dimensions of their evidence use during an assessment of their argumentation on topics not part of the intervention. One assessment was dialogic, the other an individual argumentive essay. In addition, intervention dialogs of the experimental group were studied at the beginning and end of the second year, to assess change. Both final assessments showed that experimental group students more frequently incorporated evidence - in particular, shared evidence- in their arguments, relative to the comparison groups. Also, students in the experimental group generated more factual questions that would help inform their arguments on the topic.

Analysis of experimental students' evidence use during dialogs throughout their second, evidence-focused year of the curriculum showed an increase in meta-level dialog with their peers about the use of evidence. Across the intervention dialogs and both final assessments, however, the functions which evidence served in students' argumentation remained consistent: At most one third of statements invoking evidence sought to weaken a claim of the opponents. The more common function of evidence, occurring in about two thirds of uses, was to support one's own claims. Implications are discussed regarding our understanding of how evidence is used in argument and how sustained practice in argumentation, afforded by the curriculum studied here, affects this use.