It is the nature of science to answer questions through experimentation. Once a question has been asked, research is done to see what information already exists to answer this question. After sorting through information, a hypothesis, or possible answer to the question, is created and tested. The results of this testing will either support the hypothesis or not. If the hypothesis is supported, more experiments can be run until it is confirmed many more times or disproven.
Observations and Question
You walk to school every single day. As you walk, you notice the world around you. You observe that plants grow better in certain areas, so you ask a question, even if it's all in the same split second that you make your observation.
You walk to school every single day. As you walk, you notice the world around you. You observe that plants grow better in certain areas, so you ask a question, even if it's all in the same split second that you make your observation.
Does the amount of light a plant receives affect its growth?
Hypothesis
A hypothesis is an educated guess, the key word being educated, that can be proven or disproven. If a hypothesis cannot be tested, then it is a belief. A hypothesis is often written as an if/then statement. For example, you know that plants need sunlight, so you make the following hypothesis:
A hypothesis is an educated guess, the key word being educated, that can be proven or disproven. If a hypothesis cannot be tested, then it is a belief. A hypothesis is often written as an if/then statement. For example, you know that plants need sunlight, so you make the following hypothesis:
If the amount of light provided to a plant is changed, then its growth will be affected.
Materials and Procedure
When creating a procedure, it must be detailed enough for other scientists to repeat the exact same experiment. This means that every measurement of every material and every movement in the process must be provided. The materials listed must also be specific enough that the experiment could be repeated in any location (do not assume the person repeating the experiment has a fully stocked science classroom.) For example:
When creating a procedure, it must be detailed enough for other scientists to repeat the exact same experiment. This means that every measurement of every material and every movement in the process must be provided. The materials listed must also be specific enough that the experiment could be repeated in any location (do not assume the person repeating the experiment has a fully stocked science classroom.) For example:
Materials
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Procedure
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Control
Within the experimental setup, there are parts that are kept exactly the same. These are called "constants" or "controls" because the experimenter knows that they are the same from the start. For example:
Within the experimental setup, there are parts that are kept exactly the same. These are called "constants" or "controls" because the experimenter knows that they are the same from the start. For example:
Each cup has the same amount of soil
Each cup has the same amount of bean seeds
What else from the procedure is the same for each cup?
Variables
If something varies, that means it changes. A variable is something that is changed at the beginning of the experiment, or changes during the experiment. They're are two types of variables that we consider, the independent and dependent variable.
If something varies, that means it changes. A variable is something that is changed at the beginning of the experiment, or changes during the experiment. They're are two types of variables that we consider, the independent and dependent variable.
INDEPENDENT
The independent variable is what the experimenter changes. Say to yourself, "I change the Independent variable"In the plant experiment, the experimenter is changing the amount of light. The amount of light is changed in the setup (procedure) of the experiment, so it's change is independent of natural phenomena.
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DEPENDENT
The dependent variable is what changes as a result of the independent variable. It is the factor that is measured or observed. "Dependent variable Does change"In the plant experiment, the dependent variable it the growth of the plant. This is what we expect to see change depending on the amount of light given to the plants.
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Groups
The experimental group contains the independent variable, in this case, the experimental groups would have different amounts of light.
The control group is the "normal" group and does not contain the independent variable and is used for comparison. This experiment would have a plant setup without light. The control group is used for comparison since everything else in the setups are exactly the same. This isolated the independent variable as the reason for the dependent variable.
The experimental group contains the independent variable, in this case, the experimental groups would have different amounts of light.
The control group is the "normal" group and does not contain the independent variable and is used for comparison. This experiment would have a plant setup without light. The control group is used for comparison since everything else in the setups are exactly the same. This isolated the independent variable as the reason for the dependent variable.
Results
The observations made, without any reasoning, recorded as results of the experiment. The word "because" should not be provided when giving results.
The observations made, without any reasoning, recorded as results of the experiment. The word "because" should not be provided when giving results.
Think "Quant = Count."
Quantitative results are results involving numbers. The dependent variable, plant growth, can be displayed with quantitative results like height, number of leaves, number of beans, etc.
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Qualitative results do not use numbers. For the plant experiment, this includes things like color or shape
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Conclusion - Claim, Evidence, Reasoning
Once all of the results have been reported, they can then be analyzed. The conclusion is a summary of the entire experiment including the background information, the setup, and the results. The format of the conclusion should be claim, evidence, reasoning. The claim is the answer to the original question. The evidence is a description of the experiment that directly refers to the results. The reasoning ties together the background information and the results to explain a phenomenon.
Once all of the results have been reported, they can then be analyzed. The conclusion is a summary of the entire experiment including the background information, the setup, and the results. The format of the conclusion should be claim, evidence, reasoning. The claim is the answer to the original question. The evidence is a description of the experiment that directly refers to the results. The reasoning ties together the background information and the results to explain a phenomenon.
Claim: The amount of light affects plant growth
Evidence: As seen in figure 1, plant C, which was given 25 watts of light each day grew the tallest. It grew 13cm whereas plant B . . .
Reasoning: Because the plants displayed different amounts of growth with different amounts of light, light affects plant growth.
The conclusion is also a place to talk about experimental error, changes that could be made to the experiment, and future experiments that could be done to further confirm the hypothesis. Experimental error does not mean the experimenter made mistakes, it refers to parts of the experiment that are imperfect. In the plant experiment, sources of experimental error could be that the beans are not genetically identical, the water could be measured more precisely with other tools, light affects temperature, so the temperature might have been different for each setup, etc.
The Placebo Effect
When pharmaceutical companies test new drugs, they will give the drug to the experimental group and a fake version of the drug to the control group called a placebo. If both groups have the same results, then just the action of taking a pill helps the people, not the drug. This is called the placebo effect. People think they are taking a drug, and that thought alone helps them.
When pharmaceutical companies test new drugs, they will give the drug to the experimental group and a fake version of the drug to the control group called a placebo. If both groups have the same results, then just the action of taking a pill helps the people, not the drug. This is called the placebo effect. People think they are taking a drug, and that thought alone helps them.