Lesson Notes

Lesson 1.4a Experimental Research: A Search for Cause and Effect

 

In this lesson you will learn some of the most important terms associated with psychological research. When many people think of research, whether it is in a laboratory or in the field, they usually think of experimental research. You will learn the difference between independent and dependent variables; experimental and control groups; and ways to ensure that the researcher and/or subjects do not unduly affect the outcome of the research.

Independent and Dependent Variables: In an experiment there are two twos of variables. The independent variable is the one that you can manipulate, while the dependent variable is the variable the is measured. To better understand the difference, try to think of it this way:

          The dependent variable is “dependent” on what happens to the Independent variable.

In other words, if you wanted to see if the more you drink impairs your ability to drive, then the variables would be:

          Independent variable: the amount of alcohol (1 glass, 2 glasses, etc.)

          Dependant variable: Let’s put you behind the wheel of a car and test

                                        your reaction times after each number of drinks.

As psychologists we would discover that the more you drink, the worse your driving becomes.

Now how do we really know that the alcohol is having an affect on your driving, maybe these were just bad drivers anyhow or if something else they drank or ate had an affect? In order to count for this, psychologists divide subjects into two groups – the experimental group and control group. The difference between these two is that the experimental group would be subjects who would be given alcohol, while the control group would be given no alcohol.

To make sure that there are no biases (i.e. researchers looking to prove they are right) the scientific method employs several safeguards to counter anything that may have an affect on the results. For example, in this experiment, some of our subjects may be given non-alcoholic beer to see if the effects of alcohol were just “all in their head”.

 

Read through this lesson and be mindful of how psychologists make sure that their results are accurate.

 

Lesson 1.4b  Descriptive Research: Naturalistic Observation, Surveys, and Case Studies

 

Another type of research method is Descriptive research. Many of you may have already been a subject in this type of research and not even known about it. For example, how many of you have been asked to fill out a form asking for your opinions of drugs in school or on bullying? Most likely, this was a survey (a type of descriptive research). One of the most famous examples of descriptive research was Jane Goodall who did research on the lives of gorillas. In order to get her data, Jane decided to live among the gorillas (a type of naturalistic observation).

 

Lesson 1.4c  Correlational Research: Looking for Relationships

 

Do you think that the more you study, the better your grades will be? Or, the more you exercise and eat healthy, the longer you will live? Well, you should because according to correlational research they are both true. Correlational research looks to find a relationship between two variables (i.e. Studying and grades). In this lesson, you will learn the three types of correlations and possible problems that could arise from this type of research.

 

Positive Correlation: This is where both variable move in the same direction.

Negative Correlation: This is when one variable goes up, the other goes down.

No Correlation: This results when no relationship can be found.

 

The most important thing to remember is that correlations only show a relationship between the two variables, not cause and effect. For example, high stress levels are correlated with getting cancer, BUT stress does not cause cancer.

 

Lesson 1.4d  Biological Research: Tools for Exploring the Nervous System

 

In this lesson you will explore the different methods biological psychologists use to discover information. By using different technologies, psychologists, for example, are able to look at the brain and find out what your brain is doing when it is sleeping or even electrically stimulate parts of your brain to see how you may react.

Take a look at the following flash presentation on Research Methods and Approaches in Practice to get a better understanding of this chapter.