Elements of the Scientific
Method 
Good science investigations begin with a question. The question should be one that leads to an investigation that will yield quantitative or qualitative data.
Ex. How does the height a ball is dropped affect the bounce height?
Students should complete research in order to make an educated hypothesis. Students should consult at least two or three sources which will be listed in a bibliography. Students must draw connections between their research and their project in this report.
A hypothesis is a predicted answer to the question being investigated. It should be based on scientific research and should be accompanied by an explanation. This statement will be proven valid or invalid by the investigation.
Ex. If I increase the height from which a ball is
dropped, then the bounce height will increase
because there is greater potential energy which
turns to kinetic.
Ex. I think that when the drop height increases, the
bounce height will increase, because there is greater potential energy which turns to kinetic.
Materials used in the investigation need to be listed in specific amounts and sizes. Use metric measurements of length whenever possible and give exact weights, etc.
Ex. tennis ball
metric ruler
tape
The procedure must be written in a clear, sequential manner using imperative commands. Number the steps and make sure to do multiple trials to insure valid results. Remember to control all your variables except the one that you are manipulating.
Ex.
1. Hold the meter stick vertically with the 0 cm end on the floor. Tape the meter stick to a wall if possible.
2. Hold the bottom of the tennis ball even with the 100 cm mark on the meter stick.
3. Drop the ball, observe, and determine the total bounce height of the ball (the distance from the surface to the bottom of the ball at the top of its bounce).
4. Continue till you have data for two more trials.
5. Repeat steps 2-5 for drop heights, 80 cm, 60 cm, and 40 cm.
6. Average all the data.
Variables are factors that will affect the outcome of the experiment. They must be labeled. There are three types of variables that must be considered. The independent variable is the factor that will be intentionally changed in the procedure. The dependent variable is the factor that is observed and measured to see if it is affected. Controlled variables are all the other factors in the investigation that must be controlled in the experiment so that they do not have any effect on the results. You may have to keep the length of string the same or the temperature of the liquid the same.
Ex. How does the drop height of a ball affect bounce height?
Independent variable = drop height
Dependent variable = bounce height
Controlled variables = ball, surface and measuring tool
Every project will include a data table which displays observations or measurements taken. When constructing a data table, it should be remembered that repeated trials are expected.
Ex.
Height a Ball Bounces From Different Drop Heights (cm)
|
Drop Height (cm) |
Trial 1 |
Trial 2 |
Trial 3 |
Average |
|
100 |
50 |
49 |
51 |
50 |
|
80 |
38 |
39 |
40 |
39 |
|
60 |
31 |
29 |
30 |
30 |
|
40 |
22 |
21 |
19 |
20.7 |
Ex.
Observations of Stains Treated With All Detergent
|
Material |
Trial 1 |
Trial 2 |
Trial 3 |
|
Oil |
Stain lightens slightly but is still apparent |
Stain lightens slightly but is still apparent |
Stain lightens slightly but is still apparent |
|
Mud |
Stain disappears |
Stain disappears |
Stain disappears |
|
Grass |
Stain lightens considerably but is still apparent |
Stain lightens considerably but is still apparent |
Stain lightens considerably but is still apparent |
Any investigation that involves the collection of data in the form of numbers will include a graph. Bar graphs are used to display data that is separate from other information. Data shown on a bar graph often reflect measured or counted amounts. For example, the amount of time it takes different colored ice cubes to melt would best be shown in a bar graph. Line graphs are used to display continuous data. Many experiments involving changes in temperature, time or distance can be graphed with a line graph but these graphs are only used to show trends in data. The dissolving time of a solid in a range of different temperatures would be an example of when a line graph would be appropriate. After you complete your graph, include a brief analysis of any trends or patterns in your data.
Ex.
A conclusion has four parts. First, answer the purpose question. Next, state whether your hypothesis was valid or invalid and explain. Then, include data to support this and explain. Finally, include additional questions you would like to investigate based on your findings. In addition, you can include problems that occurred during your investigation if relevant.
Ex.
The higher the drop height is, the higher the bounce height will be. My hypothesis was correct. When I held the ball at 100 cm, the ball bounced an average of 50 cm. When I held it at 80 cm, it bounced 39 cm. When I let the ball bounce from 60 cm, it bounced to 30 cm and when I held it at 40cm, it bounced to 20.7 cm. This proves that when you increase the drop height, the bounce height increases too. Next time, I would like to find out if the surface you bounce a ball on affects its bounce height.
Presentation
Now, you will assemble all of your pieces on a tri-fold backboard and prepare for your interview. Next step is going to the science fair.
J See the “Organize” section on the home page for more details.