SCIENTIFIC METHOD
-Study GuideScientific Method is a step-by-step approach to solving a problem.
1. Identify the PROBLEM
2. RESEARCH to learn about the problem.
3. Create a HYPOTHESIS to predict what you think the solution is.
4. Create an EXPERIMENT to test your solution.
5. OBSERVE and record data from your experiment.
6. ANALYZE the data to determine what your observations mean.
7. Create a CONCLUSION that explains what the purpose and outcome is of your
experiment, and offer advice on what direction further research could go in future
investigations.
CONTROLLING VARIABLES
One of the most common types of experiments contain:
1. A CONTROL group, which is used as a base for comparison to...
2. The VARIABLE or EXPERIMENTAL group, which receives a variable that is
intentionally introduced to the group to see its effect in comparison to the control group.
VARIABLES
INDEPENDENT VARIABLE is the variable intentionally introduced to the variable
group in an experiment.
DEPENDENT VARIABLE is the resulting change in the variable group that is caused by
the introduction of the independent varaible.
All other variables that may exist between the two groups need to be controlled so that
they do not compromise the validity of experiment's results. The variables are sometimes
referred to as CONSTANTS or CONTROLLED VARIABLES.
PRACTICE:
Identifying variables
Suppose the problem posed is...
Will salt water harm a typical plant?
And, the hypothesis is that...
Salt water is harmful to plant growth.
Let's pretend that an experiment was done where 100 plants of the same variety and size
were divided into two equal groups of 50 plants each.Throughout the experiment, one
group is watered with fresh water, and the other with salt water. Both groups receive the
same amount of water, the same number of hours exposed to light, and are planted in the
same soil.
PRACTICE:
1. Identify the control and variable groups.
2. Identify the independent, dependent, and at least two controlled variables in the above
experiment.
Answers:
1. The control group is the group of plants watered with fresh water, the variable group is
the the plants watered with salt water.
2. The independent variable is the addition of salt to the water. The dependent variable is
the rate of growth of the plants.
Some controlled variables (constants) are the hours of light exposure, the type and size of
plant used, the soil type, and amount of water plants received.
PRACTICE QUIZ
for upcoming quiz
1. List the 7 steps of the scientific method in the proper sequence.
2. What step does each of the following describe?
- collecting background information to form a hypothesis?
- organizing and making sense of observations?
- making an educated guess?
3. Write a hypothesis for the following problem in the proper form.
"Do seeds sprout quicker when given warmer conditions?"
4. For the following experiment, identify the control and variable groups. Then identify
the independent and dependent variables, and list at least 2 controlled variables (also
called constants).
"100 seeds of the same type were divided into two groups of 50. All seeds were planted
in the same type of soil at the same depth. All seeds received the same amount of light, as
well as the same amount of water. One group of 50 seeds were grown at room
temperature (70 degrees), while the other 50 were grown at 85 degrees."
5. Graphing - Where does the independent variable go on a graph? Where does the
dependent variable go?
6. Observations-Determine whether the following are qualitative or quantitative
observations.
- Mrs. Missal is 170 cm tall.
- Mrs. Foti is the oldest teacher on the team.
- It is raining today.
- Mrs. Bucari ran the 100 m dash in 10.2 seconds.
7. What should be included within the conclusion to an experiment?
ANSWERS BELOW!!!!!!!
1. Problem, research, hypothesis, experiment, observations, analysis, conclusion.
2.research, analysis, hypothesis
3.one example is... Seeds exposed to warmer temperatures will sprout faster than seeds at
room temperature.
4. Control group - seeds at room temp
variable group - seeds with added heat (85 degrees)
independent variable - heat
dependent variable - speed of sprouting
controlled variables - type of seed, type of soil, amount of water, amount of light, depth
of planting...
5. The independent variable is graphed on the x-axis (horizontal, across)
The dependent variable is graphed on the y-axis (vertical, up and down)
6.Quantitative, qualitative, qualitative, quantitative
7. A brief review of the purpose, hypothesis and experiement...
Discussion of whether the results indicate that the hypothesis appears correct or incorrect
(using evidence from your observations to support your conclusion)...
Ideas to improve the experiment in future investigations.