1. An Experimental Method Tutorial
Created by Lori Hokerson, Adjunct Faculty
American River College
Last Updated 6 January 2008

2. About this Slideshow: This is an interactive lecture.
Please follow the instructions on each slide.
Please keep a notepad and writing instrument handy in order to participate in the lecture activities.

3. Lecture Objectives:
By the end of this presentation, students should be able to:
Describe and apply the basic elements of an experiment.
Identify the independent variable, dependent variable, experimental group, and control group in sample studies.
Distinguish the independent variable from the dependent variable.
Distinguish the experimental group from the control group.

4. Lecture: Experimental Design
To view this PowerPoint lecture, follow the instructions on your computer screen.
Use the appropriate buttons to respond to the questions.
The lecture is automated, requiring you to click only when prompted.
You will need a sheet of paper.
Click here to Begin Lecture

5. Step 1 Calculate a bunch of statistics with the data I collected.
Psychology is a science and employs the scientific method to study its hypotheses. Therefore, researchers must use the steps of the scientific method when conducting psychological research. As a new member of the General Principles of Psychology Research Team (GPPRT), what is the first step you must take in designing a study? Click on the first step you would take.
Calculate a bunch of statistics with the data I collected.
Share with the scientific community what I found out.
Decide what it is that I’m going to study.
Select a research method, such as experimental design.

6. Step 1: Formulate What is my hypothesis?
CORRECT! The first thing you must do when designing a research study is to formulate what it is that you want to study. Here is a brief list of the information you need to consider:
What is my hypothesis?
What are the variables I am going to study?
How can I operationalize these variables?
How will I measure these variables?
To continue formulating your study, click here.

7. Step 1: Design???
OOPS!
You’ve actually skipped a step. Before you can design your study, you have to know what it is that you are going to study. Have you established a hypothesis yet? Do you know what variables you are going to measure? These questions must be answered before you can choose a research design.
Go back to the previous slide and select which step would answer the questions above. Click here to return to the previous slide.

8. Step 1: Analyze??? OOPS! You’ve jumped way ahead…
You can’t calculate any statistics if you haven’t collected any data.
You can’t collect data before you’ve designed your study.
Most importantly, you can’t design your study without knowing what it is that you want to study.
Go back to the previous slide and select which step is the first step you should take. Click here to return to the previous slide.

9. Step 1: Report???
OOPS!
You’re already at the last step of the scientific method but you haven’t done your study yet! You have no information to report to the scientific community.
First thing is first. All research studies begin with an idea, or what is known in the scientific community as a hypothesis.
Go back to the previous slide and select which step would bring you to your hypothesis. Click here to return to the previous slide.

10. Step 1- Formulate Your Study
The first step you’ve taken is to formulate your study. First you need to establish a hypothesis. Here are a few ideas:
Job Satisfaction
You’re interested in finding out what variables increase employee job satisfaction.
Motivation
You’re interested in studying variables that motivate human behavior.
Take a moment to think about each of these topics and write down a hypothesis that includes both variables…
(Click the arrow to continue)

11. Step 1 Formulate your hypothesis.
What can employers do to increase employee job satisfaction
You are getting closer and closer to your hypothesis. Remember, a hypothesis is a statement about a possible relationship between variables. It will shape the type of research design that you choose.
(Click the arrow to continue)

12. Your Hypothesis The work environment
After further reflecting on your hypothesis, you begin to define more specifically, or operationalize, the variables that you want to include in your study. Take a moment and think about how you could study the variables you have in your working hypothesis…
The work environment
Your hypothesis is now complete-
A comfortable work environment will increase employee job satisfaction.
(Click the arrow to continue)

13. Step 1 Operationalize the Variables
A comfortable work environment will increase employee job satisfaction.
This is your hypothesis and the focus of your study, but you are not done with step 1 of the scientific method. Now you have to operationalize all of the variables that will be a part of your study. How many variables do you see in your hypothesis?
Take a moment to write down the variables in your hypothesis, then click here to continue.

14. Step 1 Operationalizing Your Hypothesis
A comfortable work environment
This is the first variable that you have identified in your hypothesis, but you have not operationalized it, or clearly stated what a “comfortable work environment” means.
will increase
employee job satisfaction.
This is the second variable you have identified and again, it is not clearly stated how job satisfaction will be looked it.
(Click the arrow to continue)

15. Step 1 Your Operationalized Variables
A comfortable work environment
You have now operationalized this variable to be a work space that includes a computer with a 17 inch monitor, an adjustable computer chair, a window, desk space, flowers, and company posters/pictures on the walls of a 10 x 10 foot employee cube.
employee job satisfaction.
Job satisfaction can be measured in many ways, but you have chosen to look at the amount of work product produced by the employee as a sign of job satisfaction.
(Click the arrow to continue)

16. END STEP 1 of the Scientific Method
You have established your hypothesis
You have operationalized the variables
Which step of the scientific method will you do next?
Calculate a bunch of statistics with the data I collected.
Share with the scientific community what I found out.
Select a research method, such as experimental design.

17. Step 2: Analyze???
OOPS!
Not yet…you still don’t have any data. You need to select a design to test your hypothesis.
Go back to the previous slide and select which step would answer the questions above. Click here to return to the previous slide.

18. Step 2: Report??? OOPS! But you don’t have anything to report, yet.
Go back to the previous slide and select which step would answer the questions above. Click here to return to the previous slide.

19. Step 2: Design To continue designing your study, click here.
CORRECT! Now that you have established a hypothesis for your study and operationalized its variables, you have to decide how you are going to test your hypothesis. As you read in your textbook, there are two types of research methods that are used to conduct research- descriptive and experimental. What’s the difference between the two?
Take a moment to review your textbook, then on a sheet of paper, summarize the difference between descriptive and experimental methods, in one sentence.
To continue designing your study, click here.

20. Descriptive vs. Experimental Methods
Hopefully you came up with a sentence that is similar to this:
Descriptive research looks for any relationship between variables, while experimental research looks for a cause-and-effect relationship between variables.
Since the GPPRT wants you to look at causal relationships, you will have to select the experimental design. It is the only method that can scientifically test to determine if a causal relationship exists between the variables you are studying.

21. Experimental Method Independent Variable Dependent Variable
There are several components that must be considered when designing an experiment. To learn more about these components, click on each one below. Once you’ve clicked on each of the links below, return to this slide to continue the lecture.
Independent Variable
Dependent Variable
Experimental Group
Control Group

22. Experimental Method (Continued)
Experiments are designed to test cause and effect relationships.
The hypothesis for your study is:
A comfortable work environment will increase employee job satisfaction.
Which variable in your study is the independent variable?
Comfortable work environment
Job satisfaction

23. The Independent Variable
The independent variable must exist in the experimental method, or it is not an experiment. Remember that this method attempts to describe a causal relationship between two (or more) variables. A causal relationship means if A happens, then B happens.
A is the variable that will produce a result in B.
Simply stated, variable A causes variable B.
The independent variable is the variable that causes the change in another variable (which is the dependent variable) and is manipulated to produce the change.
(Click the arrow to return to the previous slide)

24. Independent Variable Comfortable work environment?
CORRECT! The independent variable in your study is the comfortable work environment. If you selected correctly, you probably realized that…
This variable might have a causal relationship with job satisfaction.
Your hypothesis predicts that a comfortable work environment will increase job satisfaction. Therefore the independent variable, the variable that you are manipulating, is the comfortable environment.
(Click here to continue)

25. Independent Variable Job Satisfaction?
OOPS! Job satisfaction is NOT the independent variable in your study. Remember, the independent variable is manipulated and only the experimental group is exposed to it. If all subjects are going to be evaluated on the amount of work product produced during the study, then job satisfaction CANNOT be the independent variable. Only subjects in the experimental group will receive the independent variable.
Job satisfaction is the dependent variable.
(Click here to continue )

26. The Dependent Variable
The dependent variable is the variable that is measured by the experiment. Again, the intent of an experiment is to test for a causal relationship between variables- if A happens, then B happens.
An experiment cannot determine the effect of A (or the independent variable) if its effects are not measured. Therefore, B (the dependent variable) measures those effects.
The dependent variable measures the effects of the independent variable.
(Click the arrow to return to the previous slide)

27. Dependent Variable Job Satisfaction
Job satisfaction is the dependent variable. Since there were only 2 variables in your study, this was probably easy to figure out. If it wasn’t easy, remember these four things about the independent and dependent variables:
The independent variable is manipulated.
The dependent variable is used to measure the effects of the independent variable on the subject.
The independent variable is given to subjects in the experimental group ONLY.
The dependent variable is given to all subjects.
(Click here to continue )

28. The Experimental Group
Subjects assigned to the experimental group will receive the independent variable.
Example
Remember…
Only the experimental group receives the experimental condition.
(Click the arrow to return to the previous slide)

29. The Control Group
Subjects assigned to the control group do not receive the independent variable.
Example
Remember…
The control group is identical to the experimental group EXCEPT that the subjects in this group do not receive the experimental condition.
(Click the arrow to return to the previous slide)

30. Experimental Group Example
Independent Variable
Experimental Group +
The researcher manipulates the independent variable such that the experimental group is the only group that is exposed to it.
This group gives the researcher an opportunity to see if the independent variable has an effect on the group.
(Click here to return to Experimental Group)

31. Control Group Example Control Group
Subjects in the control group are identical to subjects in the experimental group EXCEPT they are not exposed to the independent variable.
This provides the researcher an opportunity to compare both groups to see if the independent variable has caused an effect not seen in subjects within the control group.
(Click here to return to Control Group)

32. Step 2 Your Study Design
It’s time to re-visit your research study. On the sheet of paper in front of you, write down…
Your Hypothesis
The Independent Variable
The Dependent Variable
The Experimental Group
The Control Group
(Click the arrow to continue)

33. Your Study Design
Your Hypothesis: A comfortable work environment will increase employee job satisfaction.
The Independent Variable: comfortable work environment
The Dependent Variable: job satisfaction
The Experimental Group: subjects that will be placed in a comfortable work environment
The Control Group: subjects that will be placed in a standard, monotone work environment.
(Next)

34. Visual of Your Study
You’ve identified all of the necessary components to have an experiment. Now you have to put them together and explain how you are going to conduct your experiment.
(Next)

35. Step 2 Describing your methods.
You are almost done with step 2 in the design of your study. Consider the questions below:
Who are the subjects in your study going to be?
How will you recruit them for your study?
How will you assign them into the groups?
What will the subjects do during the study?
Take a few moments to answer the questions above and describe your methods, then click here for an example of a research description. Be sure to include your hypothesis!

36. Hypothesis & Subjects Example
The hypothesis of this study is that a comfortable work environment will increase employee job satisfaction. Subjects for this study were recruited from a temporary hiring agency and randomly assigned to one of the two groups. Subjects (43 male and 56 female) were between the ages of 24-30, had been unemployed from 3 months up to a year, and all resided in Sacramento, California.
(Next)

37. Procedures Example
Rented office space was renovated into two rooms. One of the rooms had a window and decorated with warm colors, flowers, and company artwork on the walls. This room served as the experimental condition. The second room did not have a window and was decorated in standard, monotone décor. No pictures or artwork appeared on any of the walls.
(Next)

38. Procedures (Continued)
Subjects were scheduled to arrive at the office one at a time and were directed to their assigned office. Half of the subjects were directed to the comfortable work environment and the other half were directed to the standard, monotone work environment.
One experimenter welcomed all subjects and showed them the cabinets where they would be filing the forms. Subjects were expecting to spend 3 hours completing forms and filing them into their appropriate filing cabinets in their office. However subjects were only required to complete 1 hour of work and then were debriefed, thanked, and sent home.
Job satisfaction was measured by the quantity of successfully completed work product, based on earlier studies which indicate that job satisfaction is positively correlated with work product.

39. End Tutorial Step 2 – Complete!
You did it! You’ve completed step 2 of the scientific method. You would complete steps 3 and 4 after the study has been completed. Review your textbook for more information about these steps.
End Tutorial

40. You’re done!
That’s it! You’ve successfully completed designing your research study and proven to be a valuable part of our team. Before you’re done, take a few minutes to do the following:
Review all of the necessary elements of an experiment.
Practice identifying those variables in other research studies.