1.

INTRODUCTION

The “Flipped classroom” is a new teaching model and different from the traditional teaching model which is “lesson taught in class” and “homework done after class”. In the “Flipped classroom”, the students acquire the knowledge by watching the teaching videos before class and discuss the difficult and important contents in class. The contents that are flipped include the statuses of teaching and learning, the roles of the teacher and the students, the time and the space of study.

The “Flipped classroom” teaching model is the outcome of the deep amalgamation of the information technology and the classroom teaching. In 1993, Eric Mazur founded the computer-assistant teach, the teacher began to change from “lecturer” into “coach”^[1]. In 2000,Maureen J. Lage, the professor of university of Miami, published the paper “Inverting the Classroom: A Gateway to Creating an Inclusive Learning Environment”, this means the naissance of the idea of “Flipped Classroom”^[2]; In 2007, Jonathan Bergmann, the teacher of Colorado middle school, practice the “Flipped Classroom”^[3]. Since 2010, “Flipped Classroom” has been used in many fields, such as lawyer educating, doctor educating, teacher educating etc. Now, with the development of MOOCs(Massive Open Online Courses) and Microcourses, “Flipped classroom” has been a popular teaching model.

In our university, Opto-electronic Technology is a required course for the student whose major is opto-electronic engineer, optical information or optical engineering. It is so important that plenty of manpower, material resources and finance have been paid on it, and now it has been the excellent course of Hunan province. The course website has been built ^[4], the teaching videos have been recorded, the animations and virtual experiments have been made. So we decided to practice the “Flipped Classroom” in this curriculum.

2.

CONTENTS OF OPTO-ELECTRONIC TECHNOLOGY

Opto-electronic Technology is a major course. It is the base of many courses, such as Fiber Optics, Opto-electronic System, Opto-electronic Experiments, etc. Its main contents are the typical radiation source, the important photodetectors, the modulation of optical signal, the detect technology, and the typical photoelectric system. Table 1 gives the title of each chapter ^[5] and figure 1 shows the relation among the knowledge points^[6].

Figure 1.

Relations of contents of the Opto-electronic Technology.

Table 1.

Contents of Opto-electronic Technology.

3.

TEACHING VIDEOS

Teaching videos are very important for “Flipped Classroom”. The fact that the students have watched the teaching video effectively before the class is the basis of the discussion in the class. In order to meet the different needs of the different students, three series of teaching videos of Opto-electronic Technology have been recorded. Table 2 shows the record types and the teachers. Studio record and screen video record are very compact and each video is shorter than 15 minutes. Classroom teaching records were transcribed when the teacher was giving lessons in the classroom, each video is about 45 minutes. Figure 2 gives the screenshots of studio record, which recorded by Shi Jianhua.

Figure 2.

Screenshots of studio recorded by Shi Jianhua.

Table 2.

Teaching videos of Opto-electronic Technology.

4.

FLASH ANIMATIONS AND VIRTUAL EXPERIMENTS

In order to help the students to understand the important and difficult knowledge points, twelves flash animations and eight virtual experiments have been made. Table 3 gives the title and the knowledge points of each animation. Figure 3 gives the screenshot of each animation. From these animations, the students can understand the structure, the principle, the characters and the applications of each important device deeply. Table 4 gives the title and the knowledge points of each virtual experiment, and figure 4 gives the screenshot of each virtual experiment. From these virtual experiments, the students may know the working process of the important systems clearly.

Figure 3.

Screenshot of the flash animations: (a) the automatic exposure of camera. (b) Laser semi-active guidance system. (c) Four-quadrant detector. (d) Photomultiplier. (e) Transfer of charge packet in CCD. (f) Transfer of voltage to frequency. (g) Measuring technique of moire fringe. (h) Frequency modulation of light intensity. (i) Roundness measurement of spindle’s surface. (j) The principle of temperature measurement by distributed fiber. (k) The system of temperature measurement by distributed fiber. (l) Modulation by reticle.

Figure 4.

Screenshot of the virtual experiments: (a) Amplitude-modulation wave. (b) Frequency spectrum amplitude-modulation wave. (c) Frequency-modulation wave. (d) The beat frequency of coherent detection. (e) Frequency spectrum of impulse. (f) Modulation and demodulation of frequency-modulation of light intensity. (g) Laser scout, alarm and disturb. (h) The detection of dim light by phase locked amplifier.

Table 3.

Flash animations of Opto-electronic Technology.

Table 4.

Virtual experiments of Opto-electronic Technology.

5.

CHAPTERS SELECTION

In order to compare the “Flipped Classroom” and the traditional teaching model, only the chapter 2 “Introduction of opto-electronic detector” and chapter 4 “Photovoltaic detector” are selected to promote “Flipped Classroom”. Other chapters are still taught by the traditional teaching model.

6.

QUESTIONS BEFORE CLASS

In order to supervise the students to watch the teaching video, some basic questions are put forward and the students should answer these questions before the class. Table 5 gives the questions before class for chapter 2 and chapter 4.

Table 5.

Questions before class for chapter 2 and chapter 4.

7.

DISCUSSION IN THE CLASSROOM

In order to improve the students’ comprehension, strengthen the students to use the knowledge to solve the practical matter, some difficult problems are discussed in the classroom. Table 6 gives the questions that are discussed in classroom for chapter 2 and chapter 4.

8.

TEACHING EFFECTIVENESS

In order to know the teaching effectiveness of the “Flipped Classroom”, a questionnaire was prepared and the students must finish the questionnaire before final examination. The result shows that about 80 percent students watched the teaching video before class, most students can understand the 75~90% content of the teaching. About 60% students like the traditional teaching model and about 40% students like the “Flipped Classroom” teaching model.

The scores of examinations are also analyzed. The result shows that the scoring averages of traditional teaching model and the “Flipped Classroom” were little difference.

Table 6.

Questions discussed in the classroom for chapter 2 and chapter 4.