Problem-based learning (PBL) is a learning experience in which students are given problems before they experience any instruction in a particular focus area (Tan, 2003; Bridges & Hallinger, 1992).  Students in PBL environments typically have greater opportunity to learn mathematical processes associated with communication, representation, modeling, and reasoning (Smith, 1998; Erickson, 1999; Lubienski, 1999). The purpose of this study is to explore the effectiveness of PBL as a mode of instruction for secondary mathematics. A quasi-experimental, non-equivalent control proxy pretest-posttest design was conducted.  Two intact classes were randomly assigned to the PBL mode whilst the other to the conventional mode.  Paas Mental Effort Rating Scale (PMERS) and Statistics Achievement Test were used to measure the effectiveness of the intervention.PMERS was developed by Paas (1992) to measure the total amount of controlled cognitive processing in which a subject is engaged during problem solving. In the experimental group, the researcher posed a a problem for the students to solve before giving instructions, notes, worked examples. Students were required to discuss in their PBL groups methods of data collection and presentation.  Students are instructed to go through their textbooks, notes on class interval prepared by the teacher. At the end of the lessons, students presented their solutions and submit their group-work to the teacher. The control group learned the same Statistics topic the conventional way.  At the end of the instruction, both the Statistics Achievement Test and PMERS were administered to both the experimental and control groups. Preliminary findings indicated that there were no significant differences in mathematics achievement and measures of instructional efficiency between the PBL and conventional group.. However findings of this study provide initiatives and support from teachers and school management on the implementation of PBL in learning mathematics and other school subjects.

Recent theories of learning emphasizes more on students-centered activities as compared to teacher-centered activities (Gibbs, 1992).  The theory dictates that it should not only involve activities such as teacher explanation, giving direction, or demonstration but rather activities such as discussion, questioning, group work, experimentation, and projects should be practiced in the classrooms. Teachers were instructed to create a student-centered learning ever since the Modern Mathematics was launched. The emphasis on student-centered learning has been spelled out explicitly in the Integrated Mathematics Curriculum for Malaysian Secondary Schools.  In addition, teaching approaches such as problem-based learning, contextual learning, self-directed learning, collaborative learning and experiential learning were suggested. Recognising the importance of these approaches, the researcher aimed to investigate the effectiveness of the problem-based learning in mathematics instruction.

Problem-based learning (PBL) is a learning experience in which students are given problems before they experience any instruction in a particular focus area (Tan, 2003; Bridges & Hallinger, 1992).  PBL is an educational methodology that emphsizes real-world challenges, higher order thinking skills, interdisciplinary learning, independent learning, teamwork and communication skills. In PBL, students experience a problem as the trigger, stimulator and motivator for learning.  PBL in secondary education became popular in 1990 in the USA and is adopted by the Illinois Mathematics and Science Academy as its instructional program (Slavin-Baden & Howell, 2004).  Students in PBL environments typically have greater opportunity to learn mathematical processes associated with communication, representation, modeling, and reasoning (Smith, 1998; Erickson, 1999; Lubienski, 1999).

The purpose of this study is to explore the effectiveness of PBL as a mode of instruction in mathematics for secondary students. Specifically, this study sought to examine effects on mathematical achievement and instructional efficiency of PBL versus the conventional instruction. A quasi-experimental,non-equivalent control proxy pretest-posttest design was conducted.  Two intact classes of form four students were randomly assigned to the PBL mode whilst the other to the conventional mode. Both groups were given a proxy pre-test and were found to be of equivalent ability in mathematics. Paas Mental Effort Rating Scale (PMERS) and Statistics Achievement Test were used to measure the effctiveness of the intervention. PMERS was developd by Paas (1992) to measure the total amount of controlled cognitive processing in which a subject is engaged during problem solving. High scores on this rating indicated high mental effort imposed on the learners hence deemed low in its instructional efficiency.

The study was carried out for four weeks with five lessons per week when each lesson spread around 40 minutes. In the experimental group, the researcher posed a a problem for the students to solve before giving instructions, notes, worked examples. Students were required to discuss in their PBL groups methods of data collection and presentation.  Students are instructed to go through their textbooks, notes on class interval prepared by the teacher. At the end of the lessons, students presented their solutions and submit their group-work to the teacher. The next lesson will be on reinforcing the previously learned concept through group discussions and discovery. The control group learned the same Statistics topic the conventional way that is teacher-centered and chalk and talk.  At the end of the instruction, both the Statistics Achievement Test and PMERS were administered to both the experimental and control groups.

Preliminary findings indicated that there was no significant differences in mathematics achievement betweent he PBL and conventional group.. It was also found that there was no significant difference in measures of instructional efficiency.between  the PBL and conventional.  Further analysis indicated that there were some positive and beneficial impact of the PBL intervention.  However findings of this study provide initiatives and support from teachers and school management on the implementation of PBL in learning mathematics and other school subjects.