Name: ____________________________________________________ Period: _____ Date: __________________
The Scientific Method
Directions: Read the following and answer the questions that follow.
The scientific method is the way scientists solve problems. Scientists begin to solve a problem by making
observations.
**For example, a scientist observes two plants growing in the shady part of his yard. He wonders if the plants
would grow taller if he placed them directly in the sunlight.
The next step in the scientific method is to make a hypothesis, which is a possible and educated explanation to the
problem they are trying to solve.
**The scientist makes a hypothesis: the plants will grow taller if I place them in the direct sunlight and out of
the shade.
After making a hypothesis, scientists will conduct an experiment to test their hypothesis.
**The scientist experiments by placing one of the plants in the direct sunlight, and leaving the other
plant in the shade.
Experiments are usually controlled, which means only one thing changes at a time and everything else stays the same.
**The amount of water is the same, the type of soil is the same, and the temperature outside is the same for
both plants.
The part of the experiment that changes is called the independent variable.
**The part of the experiment that manipulated or changed (the independent variable) is the amount of light.
The dependent variable is the result of whatever was changed (respondent).
**The dependent variable would be the plant height. The plant height changed because of the independent
variable (the amount of light)
Scientists will then record data.
**The scientist recorded the height of both plants every week.
Scientists finally make conclusions.
**After examining the data, the scientist concluded that the plant placed in the direct sunlight grew
taller because it had more sunlight.
1. What is the scientific method? ___________________________________________________________________
2. What is the first step in the scientific method? _______________________________________________________
3. Why do scientists perform experiments? ___________________________________________________________
4. What is a controlled experiment? __________________________________________________________________
_______________________________________________________________________________________________
5. What is an independent variable? _________________________________________________________________
6. In our experiment, the amount of light was changed. What other variables could be tested? ___________________
_______________________________________________________________________________________________
7. What is the final step in the scientific method? ______________________________________________________
Identifying the steps of the Scientific Method
Directions: Read the story below and answer the questions that follow in complete sentences.
A scientist saw a snake bite a mouse and then let it go. The snake left the mouse and waited until it
died to come back and eat it. The scientist wondered how the snake was able to find the dead prey. She
observed the snake’s activity and thought about what she already knew about snakes. She decided that the
snake must have been using its ability to detect body heat to follow the prey after it died. She experimented
with snakes and allowed them to feed on mice. She controlled the environment so that the snakes couldn’t
see, hear, or smell the mice. Even in this controlled environment, the snakes were able to strike the prey and
find it later. The scientist recorded data and decided that the snake did indeed follow the body heat of the
mouse in order to find it later.
1. What problem was the scientist trying to solve?
2. What was the scientist’s hypothesis?
3. How did she test this hypothesis?
4. How did the scientist control the experiment?
5. What was her conclusion?
6. Did the scientist’s hypothesis agree with her conclusion?