Scientific Method

Control Variable:

The elements within an experiment that remain constant or unchanged

Manipulated Variable:

The one element within an experiment that is changed or varied throughout an experiment

Responding Variable:

An observed change within the experiment that happens as a result of a change in the manipulated variable


How the scientific method works via experimentation

  1. Formulate a question
    • Do plants need sunlight to grow
  2. Research the question (Maybe the question has already been answered!)
    • Plants convert light into energy using chlorophyll
  3. Form a hypothesis

Hypothesis is written in a form called if...then statement (If we change this then this will change as a result)

If we adjust the volume knob on the radio, 

then the radio will play louder.

If we flick on the light switch, 

then the lights will light up.

Now we sprinkle in Manipulated Variable and Responding Variable into the hypothesis:

If the Manipulated Variable is describe change,

then the Responding Variable will describe change.

If the light given to a plant is increased then the plant growth will increase

4. Following a method or procedure carry out the experiment

  • Grow plants in dark vs. grow plant in light

5. Collect and analyze data

  • Plant that was grown in light grew 10 cm! OMG!

6. Based on data accept or reject hypothesis (Fancy-sciencey way to say the hypothesis is true or not) 

The data shows a plant grown with a light source will grown more than a plant grown in the dark.

7. Draw conclusions

  • Are there any contributing factors that may have affected the experiment?
  • Any follow up questions after the experiment
  • Is there a better way to conduct the experiment