For a science fair project some teachers require that the question be something you can measure, preferably with a number. Rather than starting from scratch in putting together a plan for answering your question, you want to be a savvy scientist using library and Internet research to help you find the best way to do things and ensure that you don't repeat mistakes from the past.
A hypothesis is an educated guess about how things work. It is an attempt to answer your question with an explanation that can be tested. State both your hypothesis and the resulting prediction you will be testing. Predictions must be easy to measure. Your experiment tests whether your prediction is accurate and thus your hypothesis is supported or not. It is important for your experiment to be a fair test. You conduct a fair test by making sure that you change only one factor at a time while keeping all other conditions the same.
You should also repeat your experiments several times to make sure that the first results weren't just an accident. Once your experiment is complete, you collect your measurements and analyze them to see if they support your hypothesis or not. Scientists often find that their predictions were not accurate and their hypothesis was not supported, and in such cases they will communicate the results of their experiment and then go back and construct a new hypothesis and prediction based on the information they learned during their experiment.
This starts much of the process of the scientific method over again. Even if they find that their hypothesis was supported, they may want to test it again in a new way. Professional scientists do almost exactly the same thing by publishing their final report in a scientific journal or by presenting their results on a poster or during a talk at a scientific meeting.
In a science fair, judges are interested in your findings regardless of whether or not they support your original hypothesis. Menu Science Projects.
Collecting Data Collecting data is an important part of your experiment. Here are some helpful links:. Science Tools Britannica Kids. How to Conduct a Science Experiment with pictures. How to write a lab report video. Precise recording and measurement of data is also of great importance for ensuring the accuracy of results and the conclusions one draws from the results.
The next step in the scientific method involves determining what the results from the experiment mean. Scientists compare the predictions of their null hypothesis to that of their alternative hypothesis to determine if they are able to reject the null hypothesis.
Rejecting the null hypothesis means that there is a significant probability that values of the dependent variable in the control versus experimental treatments are not equal to each other.
If significant differences exist, then one can reject the null hypothesis and accept the alternative hypothesis. Conversely, the investigator may fail to reject the null hypothesis, meaning the treatment has no effect on the results. Before scientists can make any claims about their null hypothesis from their experimental data or observations, statistical tests are required to ensure the validity of the data and further interpretation of the data.
Statistical tests allow researchers to determine if there are genuine differences between the control and experimental treatments. From there, they can create figures and tables to illustrate their findings. The last portion of the scientific method involves providing explanations of the results and the conclusions that can be logically drawn from the results.
Generally, this step of the scientific process also requires one to revisit scientific literature and compare their results with other experiments or observations on related topics. This allows researchers to put their experiment in a more general context and elaborate on the significance of particular results. Additionally, it allows them to explain how their work fits into a larger context in their discipline.
The scientific process does not stop here! The scientific process works through time as knowledge on topics in science accumulate and drive our understanding of particular mechanisms or processes explaining natural phenomena.
If we fail to reject our null hypothesis, then it becomes necessary to revisit the initial stages of the scientific method and try to reformulate our questions and understand why an anticipated result was not attained. The only difference between the use of this method in every-day life and in the laboratory is that scientists carefully document their work, from observation to hypothesis to experiment, and finally conclusions and peer review.
In addition, unlike problem solving outside the lab, the scientific method in the lab includes controlled conditions and variables. It is known that plant growth is affected by microbes, such as bacteria and fungi, living in their soil.
It is possible to figure out what microbes have which effects by potting plants in completely sterile soil, then adding in microbes one at a time, or in different combinations and measuring the growth of the plant. Observation and Question : There are microbes in the soil…do these affect plant growth?
Experiment : set up groups of plants in 1 sterile soil, 2 soil with the microbe added in, and 3 natural soil. Measure the growth of the plants over time, using a ruler. Conclusion : if the plants in group 2 grow more slowly than the other two, the hypothesis is supported. This needs to be backed up with statistical analysis from many plants to be considered significant. An experiment like this is not legitimate with just one plant per group.
Group 1 is a control which shows the plants can grow in the sterile soil. Group 3 is a control that shows the plants can grow under normal conditions. Group 2 is the experimental group. It would be possible to add different amounts of the microbe, or different microbes, to introduce more variables. The main point is that the researcher has something to which to compare the experimental group- the control group.
Earth science can answer testable questions about the natural world. What makes a question impossible to test? Some untestable questions are whether ghosts exist or whether there is life after death.
A testable question might be about how to reduce soil erosion on a farm. To answer a question, a scientist first finds out what is already known about the topic by reading books and magazines, searching the Internet, and talking to experts. This information will allow the scientist to create a good experimental design. If this question has already been answered, the research may be enough or it may lead to new questions.
The farmer researches no-till farming on the Internet, at the library, at the local farming supply store, and elsewhere. He learns about various farming methods; he learns what type of fertilizer is best to use and what the best crop spacing would be.
From his research he learns that no-till farming can be a way to reduce carbon dioxide emissions into the atmosphere, which helps in the fight against global warming. With the information collected from background research, the scientist creates a plausible explanation for the question.
This is a hypothesis. The hypothesis must directly relate to the question and must be testable. Having a hypothesis guides a scientist in designing experiments and interpreting data. To support or refute a hypothesis, the scientist must collect data.
A great deal of logic and effort goes into designing tests to collect data so the data can answer scientific questions. Data is usually collected by experiment or observation.
Sometimes improvements in technology will allow new tests to better address a hypothesis. Observation is used to collect data when it is not possible for practical or ethical reasons to perform experiments.
Written descriptions are qualitative data based on observations. This data may also be used to answer questions. Scientists use many different types of instruments to make quantitative measurements. Electron microscopes can be used to explore tiny objects or telescopes to learn about the universe. Probes make observations where it is too dangerous or too impractical for scientists to go. Data from the probes travels through cables or through space to a computer where it is manipulated by scientists.
Experiments may involve chemicals and test tubes, or they may require advanced technologies like a high-powered electron microscope or radio telescope. Atmospheric scientists may collect data by analyzing the gases present in gas samples, and geochemists may perform chemical analyses on rock samples.
A good experiment must have one factor that can be manipulated or changed.
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