| This qualitative case study sought to understand the benefits and limitations of using JavaSketchpad sketches in learning tasks aimed at developing reasoning and communication skills related to geometric proof in the secondary school classroom. In addition to video and audiotaped observations of student pairs, data was collected via student questionnaires and teacher interviews.;The systematic analysis of the data led to the building of interrelationships among the following elements of the learning situation: teacher, student, student partner, labsheet questions, and sketch. Categories developed by Towers (1999) to describe teacher interventions were extended to provide a more appropriate framework for analysis of the roles of JavaSketches and labsheets in the secondary school geometry program.;The study results showed that JavaSketchpad---supported activities offer several benefits. JavaSketches motivate and engage students through their interactive elements. They support exploration of geometric relationships through the provision of action buttons, dragging capabilities, and onscreen measurements. They also provide opportunities for students of different ability levels to investigate geometric ideas, and to develop further visual, analytic, and deductive reasoning skills.;When students work in pairs, the activities enable student-student and student-teacher communication through the following: sketch colour and labels aid referencing; the onscreen diagram acts as a shared image; and the sketch provides an easily accessible tool for demonstration during discussion.;Several limitations were also identified. The extent to which JavaSketches are beneficial is dependent on the skills of the sketch creator. Sketches must be carefully linked to the accompanying labsheets to be effective in guiding students to extend their geometric understanding. Additional limitations are that details cannot be added, and that geometric terminology is not displayed during use of the pre-constructed sketches.;The results of the study indicate that pre-constructed JavaSketches and the accompanying labsheets provide effective interaction opportunities for student pairs, and intervene in the learning situation in ways that parallel those of a good teacher. To support student efforts they must complement one another in the roles of focusing attention---drawing attention, prompting action---providing affordances, inviting exploration---providing alternate paths, introducing uncertainty---supporting experimentation, checking for understanding---providing a shared image.;When developed with attention to these parameters, JavaSketchpad ---centred learning situations can provide valuable opportunities for students to enhance their understanding of geometric problems. |
