We report the combined use of Wikispaces (wikis) and collaborative group problem solving (CGPS) sessions conducted in introductory-level calculus-based physics classes. As a part of this new teaching tool, some essay-type problems were posted on the wiki page on a weekly basis and students were encouraged to participate in problem solving without providing numerical final answers but only the steps. Each week students were further evaluated on problem solving skills, opening up more opportunity for peer interaction through CGPS. Students developed a set of skills in decision making, problem solving, communication, negotiation, critical and independent thinking, and teamwork through the combination of wikis and CGPS.