ESLR:  to be critical thinkers

STANDARD:   Students formulate explanations using logic and evidence.

 

 

SCIENCE & THE SCIENTIFIC METHOD

 

The scientific method offers a means of testing ideas and solving problems.  Experimentation is the heart of the scientific method.  This lesson gives you the opportunity to develop skill in using the scientific method.

 

PART I

 

The following fictional experiment demonstrates the use of the scientific method:

 

Many people in the small Midwestern town of Hootville are stricken with the disease “Buggo”.  Most of those stricken recover with in seven to nine days.

 

Buggo has been shown to be caused by the bacterium” Gotcha”.  Antibiotic “X” is a new drug that has been proven to kill Gotcha bacteria grown in a test tube.  Antibiotic X was also shown to cure dogs that were stricken with Buggo.

 

Researchers decided to test the new drug on some of the people of Hootville.  They thought that if they gave patients antibiotic X, the patients would recover more quickly than those who did not take the antibiotic.

 

The researchers prepared tablets containing antibiotic x and a second group of tablets that did not have antibiotic X (a placebo).

 

The researcher selected two groups of people who had just contracted the disease.  Twenty-five people were given antibiotic X and 25 were given the placebo.  Twenty of the twenty-five people taking antibiotic X recovered in one day.  The other five people took seven to nine days to recover – the normal recovery time for untreated patients.  One of the people given the placebo recovered in one day.  The rest of these people took from seven to nine days to recover.

 

1. What is the researcher’s hypothesis?  The hypothesis is a one sentence statement of the possible answer to the researchers question.
2. Identify the experimental group and the control group in this experiment?  The experimental group has one factor called the variable changed to learn its effect.  The control is used for comparison.
3. Make a table and record the data collected from this experiment.
4. Analyze the data collected by calculating the percent of people who recovered in one day using antibiotic X. and the percent of people recovering in one day using the placebo. SHOW YOUR MATH.
5. Write a qualitative conclusion for the experiment.
6. Write a quantitative conclusion (one using numbers) for the experiment.

 

PART II

 

Design an experiment to test the effect of fertilizer on bean production in bean plants.  The story is:

Bean growers want to increase crop yields to meet the growing demand for food.  The ACME Fertilizer Company has asked a botanist – you – to test their latest product, Growmore on bean production.

1. Write the procedure for your experiment.
2. What was your hypothesis?
3. What was your control?
4. Why did you include a control?
5. What was the variable (the one thing you changed) in your experiment?
6. Why could you only change one thing?