Lina Wu, Wenyi Lu, Ye Li Abstract—Regarding heavy video game players for boys and super online chat lovers for girls as a symbolic phrase in the current adolescent culture, this project of data analysis verifies the displacement effect on deteriorating mathematics performance. To evaluate correlation or regression coefficients between a factor of playing video games or chatting online and mathematics performance compared with other factors, we use multivariate analysis technique and take gender difference into account. We find the most important reason for the negative sign of the displacement effect on mathematics performance due to students’ poor academic background. Statistical analysis methods in this project could be applied to study internet users’ academic performance from the high school education to the college education. Keywords—correlation coefficients, displacement effect, gender difference, multivariate analysis technique, regression coefficients I. INTRODUCTION ITH the development of computer technology, playing video games and chatting online have become the core part of teens’ life for the past two decades. For instance, the average time spent on playing games increased from about 30 minutes a day in 2004, to 1 hour 13 minutes a day in 2009 [1]. As middle and high school students associate with mostly same-gender friends, girls tend to spend more time on chatting online than playing video games while boys prefer to play video games. “Video games for boys and online chatting for girls” is a symbolic phrase among parents that represents current adolescent culture. By observing teens’ behavior of spending more and more time on video games/online chat compared with less and less time on homework, parents have expressed their serious concern. The growing concern from parents has drawn extensive attention in public, especially to educational researchers. Lina Wu is with the Department of Mathematics, Borough of Manhattan Community College, The City University of New York, New York, NY 10007, USA (corresponding author, phone: 419- 509-6381; email: lwu@bmcc.cuny.edu). Wenyi Lu is with the Department of Economics, The Graduate Center of CUNY, New York, NY 10016, USA (email: wlu1@gradcenter.cuny.edu). Ye Li is with the Department of Mathematics, Central Michigan University, Mount Pleasant, MI 48859, USA (email: ye.li@cmich.edu). Researchers who are interested in the effect of playing video games/chatting online on students’ academic performance have adopted the displacement effect (or displacement hypothesis) as a theoretical base. A theory of the displacement effect explains that one activity can displace other developmental activities within a time-limited environment. This perspective has mainly been adopted by media studies and started from the early days of television [2], [3]. The basic argument of the displacement effect is that media used by children, such as TV viewing, displaces more developmentally appropriate activities for children, such as reading [4] and interaction with parents [5]. If we only adopt the basic argument of displacement effect, we can expect playing video games and chatting online to displace other valuable activities, such as doing homework. Therefore, students’ academic performance will decrease due to lack of time spent on schoolwork. However, what conclusions can we draw by analyzing actual data [6] on playing video games/chatting online and mathematics performance to examine the displacement effect? What are the outcomes from reality? Researchers who focus on the role of educational video games in learning have identified positive results of students’ academic success from video game learning compared with traditional classroom learning [7]. Researchers also pointed out educational video game players have stronger ability of problem-solving than non-players [8]. For an effect of playing non-educational video games on academic outcomes, researchers have not reached an agreement. However, the contemporary research on relationship between video games and academic performance does not take the gender difference into account. Researchers who place emphasis on parental rule to discipline teens’ study behaviors have drawn their conclusions in parent’s perspective related to gender difference. In a sample of students aged 11 to 16, Phillips et al. [9] found that male students spent more time on video games and were more likely to neglect homework than female students under parents’ influence. In a sample of college students, Burgess et al. [10] reported a negative relationship between playing video games and academic achievements, which was consistently more evident for male students compared with female students under parental rules. Applying the Statistical Technique of Multivariate Data Analysis for Studying Effects of Video Games and Online Chat on Mathematics Performance in High School W