An online system leveraging self-explanation was developed. The theoretical basis and design principles guiding the development of the system were explicated. Four evaluation studies were conducted to assess the student-generated explanations component accompanying student-generated questions (SQG) and the embedded designs. The analyzed data revealed several important findings. First, SGQ complemented by student-generated explanations (as compared to SGQ alone) was regarded as promoting learning better by a sizeable majority of the participants, and its facilitating effects on cognitive and affective aspects were noted. Second, the fact that the exact same set of cognitive and affective gains and similar patterns in the spread of responses were found from the explanation-generation for self- and peer-generated questions provided preliminary evidence supporting the "manageable versatility" design principle. Third, the result indicating that a predominant percent of the participants supported online practice on SGQ complemented by student-generated explanations substantiated the "manageable integration" guiding principle. Finally, the finding that a significantly greater percentage of the participants felt multimedia-equipped explanations to be better for SGQ (as compared to text-based explanations), both cognitively and affectively, provided preliminary evidence supporting the effectiveness of the multimedia design in terms of attaining the multiple feedback functions.