Controlled Experimental Method

Controlled Experimental Method

Deliverable Length:  2 pages

Scientific inquiry in biology starts by observing the living species around you. What separates science from the other methods of seeking truth is that it is testable (e.g., one can devise experiments to test the validity of an idea); it is falsifiable (e.g., an experiment can reveal if an idea is false); and it involves natural causality (e.g., the method involves and depends upon the natural laws of the universe which cause things to happen in a predictable and repeatable manner).

Observation: Scientific inquiry begins when something interesting gets your attention.

Question: Following an observation, a question arises in your mind. It may be something like “I wonder what?” or, “I wonder how? or, “I wonder why?”

Assignment Details

In this assignment, you will take a look at the scientific method. You will design a (fictional) scientific study to answer a specific question based upon an observation.

First, choose 1 of the following observations or questions:

Option A

Observation: During the winter, you spread salt daily on your driveway to melt the snow. In the springtime, when the lawn begins to grow, you notice that there is no grass growing for about 3 inches from the driveway. Furthermore, the grass seems to be growing more slowly up to about 1 foot from the driveway.

Question: Might grass growth be inhibited by salt?

Option B

Observation: You and your neighbor have small kitchen gardens where you both grow tomatoes. His blotchy green and red tomatoes taste much sweeter than your perfectly uniform red ones.

Question: Might tomato sweetness be affected by the green chloroplasts in the fruits?

Option C

Observation: You went to the bakery to get a loaf of bread, but all of the loaves seemed small. The baker said that he used the same recipe and tested to be sure the yeast in the dough was active, but the machine he used broke down during the kneading process. Because the bread rose, he decided that it had developed enough gluten, and he baked it off anyway.

Question: Does yeast need air to make bread rise?

After choosing 1 of the above options (observation and question), you will do some library or Internet research about the subject. Once you have become familiar with the topic, propose a testable hypothesis to answer the question, and follow the rest of scientific method to determine if your hypothesis is correct by designing a controlled experiment.

You will not actually do the experiment or collect results; rather, you will propose a workable controlled experiment and make up what would seem to be reasonable results. You will then discuss those imagined results and draw a conclusion (based upon your imagined results) about whether or not to accept your hypothesis.

Complete the steps of the scientific method for your choice of observation and question using the directions below. Use the following headings in your paper.

Introduction

The introduction is an investigation of what is currently known about the question being asked. Before one proposes a hypothesis or dashes off to the lab to do an experiment, a thorough search is made in the existing literature about the specific question and about topics related to the question. Once one is familiar with what is known about the question under consideration, one is in a position to propose a reasonable hypothesis to test the question.

Hypothesis

This is an educated guess or a best guess about what might be the explanation for the question that is asked. A hypothesis should be a 1-sentence statement (not a question) that can be tested in an experiment. A hypothesis can be stated as a prediction using an if/then statement. The ability to test a hypothesis implies that it has a natural, repeatable cause.

Controlled Experimental Method

The hypothesis is tested in a controlled experiment. A controlled experiment compares a control (e.g., the normal, unmodified, or unrestricted, or uninhibited set-up based on the observation) to one or several experimental set-ups. The conditions in the experimental set-ups are identical to the control in every way (e.g., temperature, composition, shape, kind, etc.), except for the one experimental variable that is being tested. The results obtained from the experimental set-ups will be compared to each other and to those obtained from the control. If done correctly, any differences in the results may be attributed to the experimental variable under consideration.

When designing an experiment, it is important to use multiples (replicates) for each set-up to avoid drawing the wrong conclusion. If the experiment only has one control and only one experimental setup with just one test subject in each, there is always the chance that a single living organism (test subject) could get sick or even die for reasons not caused by the experimental variable. Because living organisms are genetically different, the results from just one test subject in a given setup may not be typical for the species as a whole. This could result in errors when interpreting the results. This kind of problem is avoided by using multiple controls and multiple experimental setups with multiple test subjects.

Be sure to provide sufficient details in your method section so that someone could reproduce your experiment.

The experimental method section should also state clearly how data (numbers) will be collected during the experiment, which will be used to compare results in each test setup.

Results

Because this is a suppositional experiment, you will make up results according to what you think might happen if you actually did the experiment.

Results should include detailed raw data (numbers) rather than just a summary of the results. For example, if data are collected daily for five weeks, results should include the actual data from each day, and not just a summary of what happened at the end of the five weeks. Recorded results should match the experimental method.

Conclusion

In this section, clearly state whether you reject or accept the hypothesis based on the (imagined) results. Discuss what this means in terms of the hypothesis, such as the need for additional experiments or the practical uses or implications of the results.

References

Provide references in APA format. This includes a reference list and in-text citations for references used in the introduction section.

Give your paper a title, and identify each section as specified above. Although the hypothesis will be a 1-sentence response, the other sections will need to be paragraphs to adequately explain your experiment.