M odels are a very important part of science; they allow scientists to share information about ideas or objects that are often too large or small to be seen with the naked eye. Models also help with representation of processes that cannot be seen at all, such as much of photosynthesis. But unfortunately, models often create misconceptions such as the misrepresentation of the solar system, cells, and volcanoes. This articles discusses the values and misuse of models: A Simple Exercise Reveals Ways Students Think About Scientific Modeling.
Teachers need to explicitly discuss with students the value of models and also their limitations. This Models Laboratory Exercise will help students understand what models are fallible but very useful, and provide critical tools for studying and communicating science, Meta!Blast provides a 3D model of the cell, that can be incorporated into this lab.
One way to have a discussion on biological models with your class is to demonstrate an idea through the use of a model. The teacher may bring in pictures of models or have the students do a black box activity. Black box activities are a great way to demonstrate many ideas about the nature of science, especially models. Teachers can have students create models about what they think is inside of the black box. Here are just a few articles from National Science Association (NSTA) to help teach about black boxes:
The teacher can then have a discussion with students in which all their ideas can be heard and seen - this is done shown by putting students' ideas on the board. Once they're focused, answers may include words like model trains, plastic car models, dioramas, etc. If you don't get some science examples, rephrase your question. Science examples might include models of DNA, the solar system, the cell, landscapes, and so on.
Once the class creates a thorough list of ideas from the students, the teacher can elicit from them some of the common features of models. Features might include: models are smaller than real life, bigger than real life, simplified relative to real life, etc. Those are some of key features as they help scientists to visualize, explain, test and predict.
It may also be important to spend some more time talking about how models need to be a physical entity, that they can and often times are in science, completely incorporeal. This helps them to expand their definition of the word model to something much more abstract.
Discussing models before starting topics such as the cell and photosynthesis may help students understand the limitations of their book and the drawings depicted. Meta!Blast is a great way for students to see a cell and its organelles, and processes such as photosynthesis on a 3D plane. This can help students understand the fluidity of the cell, as well as how these processes such as photosynthesis are occurring all around them, and not just in one part of the thylakoid.