Have you ever attended an online class? Whether you are a learner or a teacher, you would surely have attended an online class where a teacher teaches a group of students. Or a video on YouTube where a passionate teacher is teaching.
A lot of effort goes into producing such videos. Many popular online learning portals offer videos as the primary teaching method for students. However, a recent study suggests that showing an instructor's face during an online class could distract the viewer.
To illustrate this, we have two teaching methods on the same topic: one where the instructor's face is visible and one where the instructor's face has been removed, and only audio has been kept. Look at this image carefully:
Which one do you think your students would learn the most from?
Option 1: With the face
Option 2: Without the face
Do you think you must put more effort into watching the instructor and his movements compared to audio? Research says yes!
Although videos are a popular choice for teaching, such classes' effectiveness needs to be looked at closely.
Figure 1 shows how a typical online class looks to the learner. We can see the talking head of the teacher in one corner of the screen. The rest of the space is taken by content such as text or diagrams. The video is supported with an audio explanation of the material.
According to Australian Educational Psychologist John Sweller, the viewer's attention gets split between reading the text on the screen and watching the visual/animation while watching a video¹.
This is called the Split-Attention Principle. When our eyes receive a lot of information simultaneously, our brain must select which information to process. This is challenging as our visual working memory is limited at any given time.
The best learning strategies avoid overloading students with any information that is excess or can distract students from focussing on the essential parts of the material.
Do you still disagree that the instructor's face can also be a distraction for learners? Let's look at several studies in this area to understand the situation better.
Researchers Bruce D. Homer, Jan L. Plass, and Linda Blakefrom New York University, United States, were interested to study the conditions under which media could be most effective as an educational tool. They investigated the effect of inclusion of the presenter's face in the lecture presentation on learners' experience in a computer-based learning environment.
They based their research on Cognitive Load Theory, which proposes inherent limitations of perceptual and cognitive systems of human beings. Our brain has a limited capacity to process information from each of the auditory and visual channels. The overall system can become overloaded if more than a few chunks of novel details need to be processed simultaneously.
For instance, Mayer's (2001) cognitive theory of multimedia learning states in the first stage, our brain has to select relevant information from visual and verbal communication. Secondly, it must organize selected information into models and integrate these models from different channels with each other and previously existing knowledge.
It follows from CLT and Mayer's theory mentioned above that redundant or irrelevant information in either channel would not help in learning and may be an obstacle by creating extraneous load.
For this experiment, a video presentation of the type that includes an audio-video presentation of a lecture with slides was chosen. The researchers suggested that this presentation may divide visual attention between the speaker's video and the slides' visuals. Thereby generating a split-attention effect and causing a more significant cognitive load.
To test this theory, researchers created two versions of the lecture. A standard video version had a video presentation of the speaker and the slides, and the other, a no video presentation that only had the lecture audio and the slide presentation. The participants could pause, play, rewind or fast-forward the presentation by pressing buttons.
26 undergraduate students from a large university were part of this study. All participants were part of an introductory psychology course.
After the presentation, the participants were asked to fill out a brief questionnaire that assessed the cognitive load they experienced while watching the presentation. They had to express the difficulty and effort experienced while watching the content.
Assessment of learning was done on two levels: 1) Recall level: that tested comprehension of the concepts in the presentation through multiple choice questions 2) Transfer level, which assessed participants' ability to apply the information presented in novel situations. The participants had to fill out responses to short-answer questions that indicated this level of learning.
The participants were randomly assigned to the video or no video presentation group. After they had viewed the content, they were given tests to measure cognitive load and learning outcomes (recall and transfer).
Table 1 shows the mean value of different measures obtained through the study for both groups.
The results show that a split attention effect was created when a video of the speaker and PowerPoint slides were both presented on the screen. Typically this condition could cause reduced learning when the cognitive lead reaches beyond a specific limit. The situation was not observed in this study; however, based on participants' experience, more mental effort was required to go through the presentation that had presence of the speaker as part of the video .
The researchers concluded from the study that conditions of greater cognitive load can be significantly detrimental to learning in cases where more in-depth learning is required and for a prolonged period. Such as in distance education classes where the students are required to take the entire course online.
No, we know from research that displaying subtitles on screen can be useful. The researchers at the University of Hong Kong studied reached this conclusion. They studied students' comprehension of audio lessons³.
Researchers Yueyuan Zheng a, Xinchen Ye a, and Janet H. Hsiao found that displaying subtitles on screen is helpful. In lectures where the main information is explained well enough through audio, subtitles enhance students' comprehension. On the other hand, the video part did not.
This suggests that the visual content, such as the instructor's face, may not be necessary for learning. Since students' attention and cognitive abilities are limited, teachers must utilize them adequately to avoid cognitive load.
To know more about why teachers should learn about cognitive load, click here
MIT's learning initiative conducted an experiment in 2018 to learn the effectiveness of reading compared to watching videos⁴. One group of participants watched a video titled "Four Fields of Listening," while the other read a video transcript that included diagrams.
After the learning period, the participants were given a post-assessment to test their retention. Here is what they found:
The group that used reading as a strategy scored better. In the same experiment, 80% of participants preferred reading books and other forms of offline learning, while only 20% preferred watching videos for learning.
During the pandemic, many children were put to watch videos on the content they would earlier read from a book. We need sufficient discussion on the impact of videos as a learning resource on children's comprehension. It is possible that forcing children to learn through videos may make them disinterested in learning.
In contrast, the value of reading and books has stood the test of time. Open Door's Thinking Classroom Workbooks are effective for this reason. These books utilize beautiful questions that encourage children's thinking while giving a lot of space for imagination.
Unlike videos, children get a lot of time to read, think and comprehend the topics. The workbooks reduce cognitive load by including only the essential information. Teachers and students create wonderful interactive sessions discussing these Math & Science questions in the classroom.
1. Instructional design in technical areas. Sweller, J. (1999). Camberwell, Australia: ACER Press
2. The Effects of Video on Cognitive Load and Social Presence in Multimedia-Learning. Homer, Bruce & Plass, Jan & Blake, Linda. (2008)
3. Does adding video and subtitles to an audio lesson facilitate its comprehension? Yueyuan Zheng a, inchen Ye a, Janet H. Hsiao (2022). https://www.sciencedirect.com/science/article/pii/S0959475221001018#:~:text=Highlights&text=Verbatim%20subtitles%20facilitate%20comprehension%20of%20audio%20lessons%20whereas%20video%20did%20not
4. Compared to reading, how much does video improve learning outcomes? https://mitili.mit.edu/news/compared-reading-how-much-does-video-improve-learning-outcomes
5. Principles of Multimedia Learning. https://ctl.wiley.com/principles-of-multimedia-learning/
Teachers try ‘teaching’ the best. Children may nod, saying that they have understood. There is a big difference between perception and reality.
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