Research Methods

Experimental Research Descriptive Methods

Correlational ResearchBiological Research

Step 3- Research Design

The hypothesis must be tested by using the appropriate research methods

‐ What type of study would best test your hypothesis?

‐ What participants will you use?

‐ What will be the procedure of your study?

The most powerful research method is the experiment,

in which an experimenter manipulates and controls the variables to determine

cause and effect.

Experimental Method

This is the ONLY research design that can examine a single factor’s effect on a particular behavior

A study in which the investigator manipulates at least one variable while measuring at least one other variable.

‐ Determines a cause and effect relationship between variables

Step 3-Designing a Study

Variables are a condition or characteristic that is subject to change either within situations or individuals

There are two types of variables in every study:

‐ Independent variable:‐ Factor that is manipulated

‐ Dependent variable:‐ Behavior/variable that is measured

Variables

Independent Variable is the variable is directly and purposefully manipulated by the experimenter

‐ This is done to see how the other variables will be affected

So, what will happen if…?

Dependent Variable is the behavior that is measured because it is expected to change due to the manipulation of the independent variable.

‐ What will happen If I move all of my front row students to the back, what will happen?

The goal of any experiment is to learn

how the dependent variable is affected by

(depends on) the independent variable.

Identify the VariableIndependent and Dependent?Independent and Dependent?

Developmental psychologists want to know if exposing children to differing amounts of public television improves their reading skills.

Did you get it?Did you get it?In this study, the amount of public television is the Independent Variable

The researchers were looking to observe a change in reading skills, which makes it the Dependent Variable

Name the Variables!

A clinical psychologist is interested in how heart rate is affected by viewing a violent film as opposed to a nonviolent film

Did you get it?

The Independent Variable is this study is the film type (violent or nonviolent)

The change in heart rate is the behavior observed which makes it the Dependent Variable

Try another one

Cognitive psychologists are interested in what types of diagrams are easiest for people to remember

What are the Variables?

The different types of diagrams are the Independent Variable

What behavior were the researchers were observing? Memory, which is the Dependent Variable

OK, Last One…

An industrial/organizational psychologist tests to see if wearing name tags makes employees happier with their work

What are the variables?

The name tags are the Independent Variable

And the observed behavior was happiness at work, which is the Dependent Variable

Step 3-Designing the Study Who will you study?

Participants in a study are individuals in an experiment whose behaviors are observed.

‐ This information will produce data

‐ All have something in common which is based on what the researcher is testing

Participants are randomly assigned to one of two groups:

1. The Control Group-(Comparison group)‐ This group does not receive the

independent variable‐ It does not receive the treatment

2. The Experimental Group- receives new treatment‐ This group “receives” the independent

variable

Descriptive Methods

This research method is used to observe and record behavior without producing a casual

explanation

Types of Research

Descriptive Methods involve describing events that already exist

- -Naturalistic Observation-Case Study-Surveys

This research method is used to observe and

record behavior without producing an explanation

Naturalistic ObservationA systematic observation what many people do under natural conditions, without interference.

Follow the link below to review a very famous

naturalistic study performed by David

Rosenhan who pretended to be mentally ill to gain

admission into a psychiatric hospital

Being Sane in Insane Places, Rosenhan (1973)

Ask questions…Surveys are another method of gathering data from a wide selection of people

A study of the prevalence of certain beliefs, attitudes, or behaviors, based on people’s responses to specific questions

Unfortunately most surveys rely on self report and not all participants are honest!

Case Study

A thorough description of the unusual person that relies on naturalistic observation but focuses on a single person intensively.

‐ These are well-suited to observe unusual behaviors or conditions

Example of a Case StudyPhineas Gage was the foreman of a railway construction gang. On 13th. September 1848, an accidental explosion blew his tamping iron through his head. The tamping iron was 3 ½ feet long and weighed 13 pounds.  The tamping iron went in point first under his left cheek bone and completely out through the top of his head, landing about 25 to 30 yards behind him.  Phineas was knocked over but may not have lost consciousness even though most of the front part of the left side of his brain was destroyed.

Phineas Gage (1848)…yes he LIVED!

Read more about Gage…why was he the focus of a case study?

Correlational Studies

A procedure in which investigators measure the correlation between two variables.

‐ Without manipulating or controlling either of them

Correlation: A measure of the strength of a relationship between two variables.

Correlational Research

Example- A researcher may examine whether a toddler’s aggressiveness is related to the number of hours spent in day care.

Correlational coefficientCorrelation indicates the strength and direction of a relationship. It allows for prediction of one variable based on the other variable.

The strength of the relationship is measured by a correlation coefficient which ranges from +1 to -1

‐ +1 – perfect positive correlation‐ 0 – no correlation‐ -1 – perfect negative correlation

In a positive correlation, the two factors move (or vary) in the same direction.

In a negative correlation, the two factors vary in opposite directions—that is, as one factor increases, the other factor decreases.

Sometimes there is no relationship between two variables—a zero correlation.

Three Types of Correlation

Did you get it?Let’s play Name that Correlation!

Answer the following questions by identifying the correlation…either positive,

negative or none

As a child’s age increases so does her height

Be able to justify this answer!

As a child’s age increases so does her

height

Positive correlation!Both variables are moving in

the same direction

The more time a person spends on a treadmill the less they weigh

Be able to justify your answer!

The more time a person spends on a treadmill the less they weigh

Negative correlationThe variables move in

opposite directions

The amount of time a college student studies

and their height in inches

Be able to justify your answer!

The amount of time a college student studies

and their height in inches

No correlation exists

“Correlation is not causation!”

Just because there is a correlation between tow variables does not mean that one variable causes

another.

What happens after the study is completed and the

data is examined?

It is time to draw a conclusion“Was I right?”

Was my prediction correct?

Researchers draw conclusions about the results of the study. Did the information support or oppose their hypothesis?

Don’t forget…this information MUST be replicated to be accepted as valid.

What happens to the information yielded in study?

If the information produced in a study supports the original hypothesis it is published in the scientific community in peer-reviewed journals.

This information is what we read about in textbooks and articles. This process allows researchers to generate NEWNEW knowledge!

Ethics in Research

Could the results of a study be BIASED?

A good scientific experiment also protects against potential sources

of error from both the researcher and the

participants

Ethnocentrism and sample bias can result in flawed data and invalid

results in the study

Avoiding Bias in Research

Absolutely, YES it is possible to bias a research study. To avoid biased information, researchers must follow the rules developed by the APA.

Ethics in Research

Ethics are the rules concerning proper and acceptable conduct that investigators use to guide their research

‐ These rules govern the treatment of animals, humans, and the responsibilities of investigators

Participants must be informed

One rule states human participants must give the researcher their informed consent before a study.

Participants must be advised about the purpose and conditions of the study- up front.

Ethics in ResearchParticipants cannot be coerced into doing something psychologically or physically harmful, or that violates standards of decency

At the end of the study, participants must go through debriefing

Why do researchers have these rules?

History of controversial psychological experiments that would now be considered UNETHICAL.

Examples:

‐ Phillip Zimbardo-The Stanford Prison Study

‐ Stanley Milgram- The Perils of Obedience

Watch the follow clip and think about why this

experiment violates ethical standards of the APA

Milgram-Perils of Obedience

Review the following clip and think about how this

experiment violates ethics in psychology

Why was this study unethical?

Stanford Prison Study

Next Module…

Biopsychology

‐ How is the nervous system organized?

‐ How do “brain chemicals” influence our behavior?