Demonstrations vs. Experiments*

While demonstrations and models can help you learn many important concepts, this science fair requires students to do an experiment following a scientific method. Here are some examples of questions that do not require an experiment but can be answered by reading a book or making a model.

  1. Can I grow bread mold? This event can be shown by a simple demonstration.
  2. Do plants need light to grow? This question can be answered by a simple "yes" or "no" and a demonstration.
  3. How does a battery work? This question can be answered by a model or demonstration.

Do not pick these kinds of questions! Instead, turn these demonstrations into experiments; the following examples are questions that can be answered by doing an experiment.

  1. What is the effect of different temperatures on growing bread mold?
    Manipulated Variable: Temperature
    Controls: Light, moisture, kind of bread, location of sample
    Measurement of Responding Variable: Amount of mold

  2. Under what kind of light do plants grow best (grow lights, fluorescent light, sunlight)?
    Manipulated Variable: Kind of light
    Controls: Kind of plant, location, moisture, kind of soil, size of pot
    Measurement of Responding Variable: Height of plant

  3. How does temperature affect the life of a battery?
    Manipulated Variable: Temperature
    Controls: Kind and size of battery, type of flashlight, length of time battery will be kept at each temperature
    Measurement of Responding Variable: Length of time the battery will operate the same flashlight bulb

NOTE: The judges will be asked to classify the projects as demonstrations or experiments. An experiment must have something that is changed (manipulated variable) and a measurement.

*From Not Just Another Science Fair by Laura Vazquez, et al.


Back to Basic Project Timeline


Questions? Contact the GPHSF Director. Last modified: 17 July 2002