An online peer learning through social media tools such as Facebook, Twitter, YouTube and Instagram has been networking interrelated undergraduates as social groups in higher learning institutions. In that respect, it has become an emerging phenomenon in the academia. Yet, not much is known about the effect of social media on the undergraduates" academic achievement. Therefore, the main purpose of this study is to identify the relationship of students' peer engagement, academic self-efficacy, social influence, peer feedback and collaboration with students' academic achievement while practising online peer learning via social media and at the same time to predict the factors that influencing students' academic achievement among undergraduate students in Universiti Putra Malaysia (UPM). The study was based on the quantitative method in nature with a correlational design using a set of the questionnaire as instrument adapted from previous studies and validated by a panel of experts. The sampling technique is stratified. A total of 376 responses were collected. The finding of regression analysis indicated that five of the variables have a significant effect while the only peer feedback has an insignificant effect. The most important factor is social influence, followed by collaboration, performance expectancy, peer engagement and academic self-efficacy. The model explained 38.9% of the variation in the academic achievement of undergraduate students at UPM. As a result, this study confirms that collaboration between peer in an online environment is valid and able to predict the academic achievement.

The increasing use of social media among tertiary students is one of the highly growing phenomena in the academia. Various studies show students' high involvement in using social media network to interact with their peers, lecturers and discussing learning materials. Full understanding of the social media and how it is being utilized in education is needed, especially in knowing the relationship between social media used and academic achievement among tertiary students as we know the tertiary students are at large used this technologies. The aims of this study is to examine the relationship between social media used (online peer learning) and academic achievement among tertiary students in one of the Malaysian public university. The study was based on quantitative method with a correlational design using questionnaires that was modified from previous study and validated by a panel of experts. The sampling technique was stratified from 17 faculties and 328 respondents involved in this study. There are positive significant low correlation between the variables measured. The highest correlation is between collaboration and academic achievement followed by the correlation between performance expectancy and academic achievement, engagement and academic achievement, social influence and academic achievement, peer feedback and academic achievement, and lastly, self-efficacy and academic achievement. Practical implications and recommendations were given to enhance the engagement of students via online peer learning.