In the Islamic Republic of Pakistan, Science is taught as a mandatory subject up to the elementary level and this subject is considered a most critical subject for young children for scientific thinking and to develop future scientists. Predominantly, the conventional method is being practiced for teaching science by a single teacher in a classroom in Pakistan but the preferred method of science teaching in developed countries is collaborative teaching to attain the desired results. The leading aim of the existing research study was to explore the effect of collaborative teaching methods on students’ achievement in a science subject. Under the positivism paradigm, an experimental research design was used to conduct this quantitative investigation. To conduct this experiment, a pretest Posttest Control Group Design was used with control (n=30) and experimental (n=30) groups selected randomly from the 5th grade of Government High School Derianwala, Narowal, Punjab. The self- developed and validated test was used to measure the learning achievements of the 5th -grade student in a science subject. Collaborative Teaching (CT) was used with the experimental group, whereas the control group performed identical procedures using the lecture teaching style (TTM). “Science Achievement-Tests (SAT)” was used as pre & posttest. To measure the magnitude effect of the collaborative teaching method on student’s achievement in a science subject Independent Sample t-tests and Paired sample t-tests were used. The result revealed that there was a significant means score difference was inspected on the control and experimental groups. The findings revealed that the target model is effective to improve students’ academic achievements in general science. Results proved that instructional practices prescribed in the TARGET model also improved students' achievement in the subject of general science. Recommendations were made based on the findings of the study. It is, therefore recommended to arrange workshops, seminars, and teacher training programs to make teachers aware of the mastery goal structure of instructional practices delineated in the TARGET model. In Pakistan single teacher teaching is being practiced in schools. Findings show that CT is a better alternative to single-teacher teaching of science. It is recommended that pre-service teachers’ training institutions may include CT in the course of ‘Methods of Teaching’ with a focus on the teaching of science. The topic may include the effectiveness of CT, how it takes place, how to develop collaborative lesson plans and how to practice CT in the classroom. The present study used one teach-one assist, model of CT. It is suggested that further research in the context of CT may use other collaborative settings such as alternative teaching, parallel teaching, team teaching, station teaching, etc. The research study solely looked at students' academic performance in general science at the fifth-grade level. Additional research can be done to evaluate the efficacy of collaborative teaching in connection to other factors including self-esteem, attitude toward subjects, peer relationships, social skills, and academic motivation for other subject areas.

Key Words: Collaborative teaching, learning achievements, 5th grade, a science subject, experimental research design.