This paper presents the study’s mixed methods designed to explore how students’ English proficiency, online instructor guidance and online collaboration influence the students’ online learning in an introductory information technology course offered by Hong Kong’s cyber higher education. The design of mixed methods used in this study mainly adopted Creswell and Plano Clark’s (2011) follow-up explanations variant of the explanatory sequential design of mixed methods. The reliability and validity of research, which have been discussed in both quantitative research and qualitative research, have to be reconsidered for mixed methods in order to reflect the multiple methods of establishing the research’s trustworthiness. This paper discusses these issues. So far, the major findings of this research using the mixed methods are presented in Wong’s (2015) quantitative phase, which revealed that students’ English proficiency exhibits the largest effect while online instructor guidance and online collaboration have a moderate effect on the students’ learning in cyber education. These quantitative findings provide implications for the qualitative phase of the mixed methods as a follow-up to explore the cause–effect relationship between the variables and the students’ learning in cyber education.