Active learning is listed as one of seven principles to improve undergraduate education by Chickering and Gamson (1987).
Bonwell & Eison (1991) defined active learning as anything that "involves students in doing things and thinking about the things they are doing” (p.2).
Active learning is “the process of keeping students mentally, and often physically, active in their learning through activities that involve them in gathering information, thinking, and problem solving” (Collins and O'Brien, 2003, p.5).
Instruction should employ active learning strategies and techniques that require learners to develop critical thinking skills in concert with information literacy skills. Planning such active learning strategies and techniques should be carried out collaboratively with faculty to increase overall student engagement and to extend opportunities for a more reflective approach to information retrieval, evaluation, and use.
- ACRL Guidelines for Instruction Programs in Academic Libraries
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Designs for Active Learning by 
Practical Pedagogy for Library Instructors by 