Enrollments in K-12 online programs have experienced explosive growth as policymakers view online learning as a viable means to education. This rapid growth presents practitioners with challenges as well as opportunities to explore what constitutes best practices in K-12 online learning. This study explored the relationship between interaction type and academic achievement and interaction preference and academic achievement. This mixed methods study was conducted at Florida Virtual School, a recognized leader in K-12 online learning. The interaction patterns and frequencies of students enrolled in six sections of a Spanish I course were observed and analyzed. A web-based questionnaire, The Interaction Preferences Survey, allowed participants to self-report their interaction preferences. Linear regression analysis demonstrated positive and significant links between the frequency of learner-learner, learner-interface, and learner-content and the achievement of participants. Moreover, no links were found between interaction preferences and academic achievement. Qualitative data provided emergent themes for learner-learner and learner-instructor as well as learner-content interactions. The relationship between the different demographic variables and achievement was explored using crosstabs. The findings of this exploratory study directly support constructivist and social presence theoretical paradigms, augment current literature, and provide practical recommendations for instructional designers and educators in the field of K-12 online learning.