eng Science and Education Publishing American Journal of Educational Research 2327-6150 2016-12-21 4 19 1295 1299 10.12691/education-4-19-3 EDUCATION20164193 article Chih-Hsien Huang huangch@mail.mcut.edu.tw 1 Ming Chi University of Technology In this paper we report a study concerning examples as mediating artifacts in conjecturing. We used activity theory as an analytical framework to analyze students' behavior and the process of conjecturing. The results show that through the guidance of proceduralized refutation model, most of the students could find the common properties by generating examples, and develop the ability of generalization and further made conjectures. http://pubs.sciepub.com/education/4/19/3/education-4-19-3.pdf activity theory example proceduralized refutation model