For example: if you want to test the effect of a certain fertilizer on radish plants growth, you create two groups of radishes, the first, the control group and the second, the experimental group. The two groups are treated the same (irrigation, light, etc.) besides only one factor, the fertilizer which is applied only to the radishes belonging to the experimental group. The fertilizer applied is called the independent variable whereas the outcome (the growth rate of the radishes in the experimental group) is called the dependent variable.
The Parts of an Experimental Science Fair Project - The Scientific Method
There is no need to follow this exactly, but as a general rule, you will find that judges expect each of these sections:
Table of Contents List the main sections, and their page numbers.
Abstract
This is the last section that you will write. In 250 words or less, write a brief description of what you have done, and what you learned. You need to detail in brief the purpose, the procedures and measurements, the results, and your conclusions. The aim is to give the reader a quick understanding of your work.
Research Report This section shows the background information you gathered from library research or the web. This is the background that you have established before you started and helped you to formulate the purpose and hypothesis of your experiment.
Purpose
This details the problem you were trying to solve, even though this is probably obvious from your title, but it should also say why you thought this was a problem worth solving, and the benefits that might be obtained from solving the problem.
Hypothesis
"Hypothesis" means "what do you expect to happen in your experiment?" Suppose your research question is, "what happens to seeds if I change the temperatures they are kept at before they are planted?" The hypothesis might be "the higher the temperature that seeds are kept at, the quicker I expect them to sprout."
It's important to word your hypothesis correctly. For example, don't say "higher temperatures are better for seeds." "Better" cannot be measured. Decide on a hypothesis that can be proved in a measurable way. For example, "higher temperatures will make the seeds sprout faster."
It is perfectly fine for your experiment to disprove your hypothesis. If something unexpected happens during your experiment, the project doesn't need to be trashed. You just discovered something new and showed that what we expect is not always what we get.
The hypothesis is a crucial component of the scientific method since its validity could be tested by statistical means.
Materials
List here all the materials you used to perform your experiment.
Procedure
The procedure is how you plan to do things: how you are going to conduct your experiment.
An experiment can only have one independent variable. That means you can only change (test) one condition in each experiment.
For example, with the seed-sprouting experiment, if your independent variable is the temperature at which the seeds are stored before you plant them, treat each group (the experimental and control) of seeds the same before and after you plant them, the same storing conditions and make sure all of the seeds get the same amount of light and water after you plant them only besides your independent variable - the storage temperature of the seeds.
If there's more than one variable, the experiment becomes flawed. It can be hard to figure out what other conditions must stay the same. But it may help to think it through before you start your experiment.
Also think about how long your experiment will take before you decide on your procedure. If you only have a few weeks to do your experiment, don't decide on a procedure that will take months to carry out.
Think about your "sample size." How many seeds will you test at each temperature? Allow a big enough sample so you can have a few duds in each group.
Take in account that in order to avoid coincidental affects on your experiment you will need to repeat your experiment a few times – this procedure is called “repetitions”.
Once you decide on a procedure, write it down step by step. That way, you can prove what you did and can follow the same procedure if you need to repeat the experiment.
Results
This is where you collect the information or data from your experiment outcomes. Your data should be in numbers, not just what you see. For example, say that some of your plants grew 1 centimeter the third day. Don't say that the plants "look bigger today than they did yesterday." Words like "bigger" mean different things to different people, so reporting your results using only words can lead to confusion. You want to tell people exactly how much your plants grew.
You may display your data in a table or graph. Keep all your results in one notebook (logbook).
Conclusions
It can be hard to understand the difference between results and conclusion, but the two are very different.
Results are the specific data collected during the experiment. The conclusion is what you learned from doing the experiment, and what the results mean. You might also think of the conclusion as a summary. In just a few sentences, you need to explain what happened in your experiment and whether it agreed with your hypothesis.
Did your data (the measurements you took) support your hypothesis? If not, that's a result, too. It doesn't mean that the experiment didn't work. Also, consider other possible explanations for your results. Did your treatment kill your plants or was it that you left them outside and some insects ate some of the leaves? You're not out to "prove" your hypothesis but to test it. Think more along the lines of "here's what I thought was going to happen and here's what actually happened." Then go on to explain why you think things happened the way they did.
Acknowledgements
If people helped you, say so. List them by name, and state briefly what they did to help. It is normal to list them by alphabetical order of surname. For email contacts, list the email addresses as well. As a rule, keep this section brief.
Bibliography
This is an alphabetical list of sources of information used to form a hypothesis, design your experiment, and compose your research report. List all the details that would be needed to help somebody else find that same piece of information. You will usually find that there are rules describing how the entries are to be written.
Examples for the scientific method
http://www.selah.k12.wa.us/SOAR/SciProj2002/KiereaM.html
http://www.virtualsciencefair.org/2004/walk4d0/public_html
The Parts of the Descriptive and Building Science Fair Types
The structure of the descriptive and the building types could be different from the experimental one since not all the components are applicable here. For example if your topic is "what is genetic engineering?" take in account that a hypothesis is not applicable since it could not be tested by statistical means. And the same applies for the display board, etc.
