| The wide application of instructional videos are promoted by the rapid development of the massive open online courses. The design, development, and application instructional video have been the focus of multimedia learning study.Signaling principle is one of the most important principles of multimedia learning theory, which would have a very important impact on the learning effect. This study,based on the multimedia learning theory, added three forms of signal into instructional video to explore whether signal will impact the learning of instructional video, whether the difference of signal form will cause the different impacts, which including visual signal, verbal signal and visual combined verbal signal. In this study, two experiments were conducted to explore the impacts, caused by signal, to learning effect, cognitive load, satisfaction and attention, so as to figure out the best signal design in instructional video.The first experiment, combining the eye-tracking technology and questionnaires,attempted to study the impact to learning of instructional video, which may cause by the difference of signal forms. This experiment, randomly choosing 80 undergraduates as participants, adopted the between-subject experiment design to explore how the instructional video without signal, with visual signal, with verbal signal, with visual combined verbal signal, impacted the learning effect, cognitive load, satisfaction and attention. Results showed that the types of instructional video with signal are significantly better than the types without signal on retention test and transfer test performance. The types with visual signal caused significantly increase in cognitive load. However, there is no difference be found out in satisfaction. The types with signal would not increase the attention of participants to the instructional video, but would optimize attention apportion, especially the form of verbal signal.The second experiment applied these four types of instructional video under real flipped classroom teaching environment, whose goal was to test and verify the impact caused by the signal in instructional video was solidity. This experiment conducted in four classes, including 118 undergraduates. And the students in different class watched the four instructional videos with different signals, including without signal, with visual signal, with verbal signal, with visual combined verbal signal. All the students took the learning test, filled in the questionnaire of cognitive load and the questionnaire of satisfaction. Results showed that, under the real leaning environment, there was no diffidence between these students came from different class on retention test performance, while there was significantly diffidence on transfer test performance,especially those students who watched the instructional video with visual combined verbal signal performed best. Moreover, there was no diffidence be found in cognitive load or satisfaction, which revealed the forms of signal would not cause impact to cognitive load or satisfaction of students.In the two experiments, the author drew the following conclusions: 1. The signal in instructional video could optimize attention apportion, especially the form of verbal signal could lead student pay more attention to the vital information faster. 2. The instructional video with visual combined verbal signal could improve learning effect,especially the performance of transfer. 3. The visual signal in instructional video would increase the cognitive load of students.This study, designed from the perspective of interdisciplinary, explored one of the most important elements of instructional video—signal. The result confirmed the effectiveness of signal, which would be impacted by the form of signal. The conclusion of this study could enrich the theoretical research about instructional video, as well as,could provide valuable advice on the instructional video design. |
