The purpose of this study was to investigate the effect of authentic assessment, an approach used in Scientific Research Methods, on problem solving skills of prospective classroom teachers. The participant groups of the study consisted of sophomore prospective teachers who study at Dicle University in the Ziya Gökalp Education Faculty Classroom Teaching Department during 2013-2014 academic spring term. The two classrooms in the department were randomly assigned as experimental group (Group B) and control group (Group A). The experimental group was given authentic tasks and asked to do them group work. The authentic tasks fulfilled by prospective teachers were analyzed in accordance with the authentic assessment approach. Authentic assessment tools such as self-assessment, group assessment, portfolio assessment, teacher-peer assessment, weekly performance assessment, and student journals were used in the experimental group. Meanwhile, control group activities were based on a subject-oriented curriculum design and teacher-centered traditional practices and assessment were carried out. Methods like verbal lectures, discussions, and question-answers were used. In addition, the evaluation process was conducted on the mid-term exam essay in traditional sense. While the pre-test and post-test results of the experimental group indicate a statistically significant positive difference for the post-test, the difference between pre- and post-test results for the control groups were not found to be statistically significant. Moreover, a comparative analysis of adjusted post-test results based on pre-test results of experimental and control groups indicated a statistically significant positive difference in favor of experimental group.