Research Methods Experimental Research Descriptive Methods Correlational Research Biological 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 • Variablesare 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 Variableis 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? • Developmental psychologists want to know if exposing children to differing amounts of public television improves their reading skills.
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 StudyWho 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: • The Control Group-(Comparison group) • This group does not receive the independent variable • It does not receive the treatment • 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 Observation • A 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 Study • Phineas 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.
Example- A researcher may examine whether a toddler’s aggressiveness is related to the number of hours spent in day care. Correlational Research
Correlational coefficient • Correlation 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
Three Types of 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.
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 correlation The 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 NEW 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 consentbefore a study. • Participants must be advised about the purpose and conditions of the study- up front.
Ethics in Research • Participants 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