MOS: The Critical Elements of Doing Effective Classroom Demonstrations
Shmaefsky, Brian R., Journal of College Science Teaching
The basis of the JCST Favorite Demonstration Column is to promote the use of classroom demonstrations in college science teaching. Demonstrations can be an integral component of a student's classroom experience. Plus, they are an entertaining distraction from the term-laden content typical of college science courses. However, it is important that demonstrations are carried out in a manner that contributes to the students' learning. Usually, there is little time in the curriculum for frivolous demonstrations. Futhermore, demonstrations done solely for fun detract from subsequent "serious" demonstrations and laboratory sessions. The "fun" should be the process of watching the principle in action.
There is a wealth of evidence showing that students can remember many of their science class demonstrations for countless years. This is a good testimony to the emotional impact of demonstrations. More importantly, students get a lifelong recollection of the concept reinforced by the demonstration. Educational literature is replete with information about effective and unproductive ways to carry out demonstrations. One way to make demonstrations into an effective teaching strategy is by taking a MOS approach.
What is MOS?
MOS, or Minds-On-Science, is the foundation of conducting educationally valuable science demonstrations. It is a teaching strategy equally effective as hands-on-learning. Plus, it proves much more effective at reinforcing abstract science concepts than traditional lectures, readings, and audiovisual presentations. MOS has the following characteristics:
* Focuses on core concepts of science
* Uses existing knowledge to build upon new information
* Facilitates understanding of abstract ideas
* Allows students to formulate scientific thinking processes
* Encourages students to share what they observed with others to assess the universality of their understanding
* Stimulates students to question and answer scientific observations
* Brings in higher-order thinking skills such as analysis and synthesis
Science demonstrations are not more than a dog-and-pony show unless they are integrated with and supported by effective pedagogical theory. Traditional demonstrations take on an authoritarian atmosphere. The instructor generally introduces the concept that then uses the demonstration to tell the students how the principle works. This provides no more information than the lecture and in some cases adds elements of confusion or misconception.
How to do MOS
Adding MOS to a demonstration simply means turning the demonstration into an inquiry activity. However, even with the best-designed demonstration it must not be assumed that students have gained value from the inquiry session unless they are assessed during and after the activity. The following pedagogical questions should be addressed before doing any lecture demonstration:
* Does the demonstration fit at least one principle of the lecture topic?
* Does it demonstrate one variable at a time?
* Does it accurately represent the concept?
* Is it reinforcing an abstract concept that cannot be effectively taught with words?
* Are the concepts being portrayed self evident from the demonstration, or is it necessary to clarify with explanation?
MOS is easily added to a demonstration by working in the following elements:
** Introduce the topic by simply stating. "We are going to learn the principles of ______ today."
* Then say, "Before discussing how this principle works, let's look at a demonstration of the principle."
* Start the demonstration, announcing each step to the class. For example, say, "Now I am adding the ______. Next, we shake and add some ______." Tell students to write what they observed with each step. Do not give away the principles of what is going on! …