A flipped classroom is an instructional strategy and a type of blended learning that reverses the traditional learning environment by delivering instructional content, often online, outside of the classroom. It moves activities, including those that may have traditionally been considered homework, into the classroom. In a flipped classroom, students watch online lectures, collaborate in online discussions, or carry out research at home while engaging in concepts in the classroom with the guidance of a mentor. A flipped classroom is an instructional strategy and a type of blended learning that reverses the traditional learning environment by delivering instructional content, often online, outside of the classroom. It moves activities, including those that may have traditionally been considered homework, into the classroom. In a flipped classroom, students watch online lectures, collaborate in online discussions, or carry out research at home while engaging in concepts in the classroom with the guidance of a mentor. In the traditional model of classroom instruction, the teacher is typically the central focus of a lesson and the primary disseminator of information during the class period. The teacher responds to questions while students defer directly to the teacher for guidance and feedback. In a classroom with a traditional style of instruction, individual lessons may be focused on an explanation of content utilizing a lecture-style. Student engagement in the traditional model may be limited to activities in which students work independently or in small groups on an application task designed by the teacher. Class discussions are typically centered on the teacher, who controls the flow of the conversation. Typically, this pattern of teaching also involves giving students the task of reading from a textbook or practicing a concept by working on a problem set, for example, outside school. The flipped classroom intentionally shifts instruction to a learner-centered model in which time in the classroom is used to explore topics in greater depth and create meaningful learning opportunities while students are initially introduced to new topics outside of the classroom. In a flipped classroom, 'content delivery' may take a variety of forms. Often, video lessons prepared by the teacher or third parties are used to deliver content, although online collaborative discussions, digital research, and text readings may be used. It has been shown that the ideal length of the video lesson to be is eight to twelve minutes. Flipped classrooms also redefine in-class activities. In-class lessons accompanying flipped classroom may include activity learning or more traditional homework problems, among other practices, to engage students in the content. Class activities vary but may include: using math manipulatives and emerging mathematical technologies, in-depth laboratory experiments, original document analysis, debate or speech presentation, current event discussions, peer reviewing, project-based learning, and skill development or concept practice Because these types of active learning allow for highly differentiated instruction, more time can be spent in class on higher-order thinking skills such as problem-finding, collaboration, design and problem solving as students tackle difficult problems, work in groups, research, and construct knowledge with the help of their teacher and peers. A teacher's interaction with students in a flipped classroom can be more personalized and less didactic, and students are actively involved in knowledge acquisition and construction as they participate in and evaluate their learning. In 1993, Alison King published 'From Sage on the Stage to Guide on the Side,' in which she focuses on the importance of the use of class time for the construction of meaning rather than information transmission. While not directly illustrating the concept of 'flipping' a classroom, King's work is often cited as an impetus for an inversion to allow for the educational space for active learning. Harvard professor Eric Mazur played a significant role in the development of concepts influencing flipped teaching through the development of an instructional strategy he called peer instruction. Mazur published a book in 1997 outlining the strategy, entitled Peer Instruction: A User's Manual. He found that his approach, which moved information transfer out of the classroom and information assimilation into the classroom, allowed him to coach students in their learning instead of lecture. Lage, Platt and Treglia published a paper entitled 'Inverting the Classroom: A Gateway to Creating an Inclusive Learning Environment' (2000), which discusses their research on flipped classrooms at the college level. In their research focusing on two college economics courses, Lage, Platt, and Treglia assert that one can leverage the class time that becomes available from the inversion of the classroom (moving information presentation via lecture out of the classroom to media such as computers or VCRs) to meet the needs of students with a wide variety of learning styles. The University of Wisconsin-Madison deployed software to replace lectures in large lecture-based computer science course with streaming video of the lecturer and coordinated slides. In the late 1990s, J. Wesley Baker was experimenting with these same ideas at Cedarville University. He presented a paper discussing what he termed the 'classroom flip' at an education conference in the year 2000 in what may be the first published mention of the word 'flip' associated with this model of teaching and learning. Kaw and Hess published a paper in 2007 to compare the effectiveness of 4 instructional modalities for a single topic of a STEM course -(i) traditional lecture, (ii) blended (what they called 'Web-enhanced lecture'), (iii) Web-based self-study and (iv) flipped (what they called 'Web-based self-study and classroom discussion'). Statistical analysis of the assessment data indicated that the second modality, in which Web-based modules for instruction were used during face-to-face lecture delivery mode, resulted in higher levels of student performance and satisfaction.