This dissertation explores how country-level cultural values are associated with gender differences in the enrollment in and completion of science, technology, engineering, and mathematics (STEM) Massive Open Online Courses (MOOC), national achievement in mathematics and science, and students' science achievement. Study 1 explored how gender-equal culture and economic development moderate the gender differences in STEM MOOC enrollment and completion across countries. This study provides evidence supporting MOOC democratization. Using multilevel logistic regression on the HarvardX-MITx Person-Course de-identified dataset, this study found that while females were less likely than males to enroll in STEM MOOCs, they were equally likely to complete them. Further, a higher probability to enroll in STEM MOOCs and smaller gender gaps in STEM MOOC enrollment and completion were found in less gender-equal and less economically developed countries. Study 2 investigated the relationship between cultural values and national achievement in mathematics and science. Using cluster analysis and Analysis of Covariance (ANCOVA) on the Programme for International Student Assessment (PISA) 2015 and World Value Survey (WVS) wave 6 datasets, study 2 found that country-level valuing science and technology and thriftiness were positively associated with while worrying about the availability of education and trying to make parents proud were negatively associated with national achievement in mathematics and science. Four cultural value profiles were identified and the highest achieving cultural value profile was high in valuing science and technology and thriftiness, low in trying to make parents proud, and about average in worrying about the availability of education. Study 3 explored the relationship between country-level cultural value profiles, gender, self-concept of science ability, utility value of science, and individual student's science achievement. Using Hierarchical Linear Modeling (HLM) on TIMSS 2015 8th grade and WVS wave 6 datasets, study 3 found that country-level cultural value profile was significantly associated with individual student's science achievement and country profile moderated gender differences in students' science achievement, females and males performed equally well in science, and self-concept of science ability and utility value of science are positively associated with students' science achievement. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]