Research Methods Experimental Studies

1. Research MethodsExperimental Studies Ms. Carmelitano

2. Bell Ringer • Bell Ringer: • Read the following, 1) what ethical considerations had to be taken into account when conducting this? 2) What was ethically done wrong 3) what sampling technique was used • “A researcher wants to study the long term effects of abuse on children. They hypothesize that children who are abused will becomes abusive when they are older. The researcher gather participants by asking one member of a group counseling group to bring others into the study. • The researcher asks the participants to sign consent letters detailing the procedure and aim of the study. After conducting initial interviews, the researchers observe the participants over 10 years, periodically interviewing them about current relationships. The researchers find that the worst the abuse as children, the more likely the participant was to be abusive in the future. The researcher published their findings, revealing the names of each of their participants.”

3. Study Vocabulary • Aim: The reason why the study is done • Independent Variable: the variable that the researcher manipulates • Dependent Variable: the variable that is measured after manipulation • Control: A group that does not receive the new treatment being studied and which is compared to the group that does receive the new treatment

4. practice • What is the Aim, Control, IV, and DV of the following: • A researcher sets up a study to test whether watching violent films on TV increases a child’s likelihood of behaving violently. They create three different test groups. One group of children are instructed to watch a “American Horror Story” (A violent television show) three times a week. One group of children are instructed to watch “Dora the Explorer” three times a week. One group of children are instructed to not change their television habits.

5. Operationalized Variables • An operationalized variable is one that is specific to the experiment • When you write it, you will make reference to the specific variables you are studying in your psychological study.

6. Example • AIM: Does listening to Mozart Music increase a person’s ability to perform well on a spatial reasoning test? • Method: A researcher instructs 3 groups to take a spatial reasoning test, their accuracy is recorded. One group then listens to 5 minutes of Mozart music, one group listens to 5 minutes of Hip Hop music, one group sits in silence for one minute. Then the 3 groups finish the test, and their accuracy is again recorded. • Independent Variable: Music • Dependant Variable: Score • Operationalized IV: Whether a participant listens to Mozart music or Hip Hop music before taking a spatial reasoning test • Operationalized DV: The score on a spatial reasoning test

7. hypothesis • Experimental hypothesis predicts the relationship between the independent and dependent variables • H1 • Null hypothesis: states independent variable will have no effect on dependant variable or any change in dependant variable will be due to chance • H0 • Operationalized hypothesis: Hypothesis makes specific reference to the variables studied • H1

8. Example • H1: Exposure to violence on television as a child will increase the likelihood of a child becoming a violent adult • H0: Exposure to violence on television as a child will not increase the likelihood of a child becoming a violent adult, or any violent actions as an adult will be due to chance • Operationalized H1: Exposure to one hour of violent television three times a week will increase the likelihood of a child to commit 2 or more violent acts as an adult • Operationalized H0: Exposure to one hour of violent television three times a week will not increase the likelihood of a child to commit 2 or more violent acts as an adult, or two or more violent acts as an adult will be due to chance.

9. Different types of experiments • When preforming a study it is important to understand what type of experiment you will do • Your experiment will depend on what you are studying

10. Laboratory Experiment • An experiment in which variables are highly controlled by the researcher. Participants are usually aware that they are taking part in an experiment, and know that they are being observed and recorded by the researcher • Pros: • Researchers are able to have strict control over variables and control • Experiment easier to replicate • Cons: • An “artificial world” is created, participants may have acted differently in a similar situation in the real world (In psychology we say that there is little ecological validity • Participant bias: participants know they are being observed, so may try to give the researcher the answer they think they are looking for

11. Field experiment • An experiment that takes place in a natural environment, but the researchers still manipulate variables • Example: A researcher wants to test how a person reacts to helping people • The researcher places an actor in a subway who pretends to faint • The researcher observes the reactions of the people in the subway • Pro: • There is ecological validity: Meaning the researcher is able to witness a “natural reaction” of participants. • Con: • Researchers may not be able to control every variable, so there may be more than one occurring • Participants do not always know they are a part of an experiment, so the researcher has not gained consent

12. Natural experiment • The researcher observes naturally occurring variables in the natural world • Example: A researcher wants to study the long term effects of child abuse • They interview children who have been abused, and then conduct a longitudinal study in which they monitor the child's behavior as they enter into school • Pros: • Researchers can conduct studies that would be un-ethical to produce artificially (because the Independent Variable causes harm to the participant) • There is ecological validity • Cons: • The researcher cannot control all of the variables • They may have to made correlations: when the link between a behavior and a variable is made by assumption

13. Correlation Study • When a researcher collects data showing relationships between 2 variables without creating an experiment • A positive correlation: when both variables are affected the same way (both increase or both decrease) • A negative correlation: when one variable increases and the other decreases • Pros • The researcher is able to conduct research on variables that are difficult to manipulate in a lab, or that would be un-ethical to manipulate • Cons • Many variables may be involved in the relationship, so researchers may not know what really caused the results

14. Correlation Example: • A researcher wants to understand if a child’s performance in school can be affected by the time watching television. • They conduct a study in which they ask high school students to record how many hours of television they watch in a week • The researcher also looks at the students overall school averages • They find that the hours of watching television negatively correlate to overall averages. Meaning as television viewing time goes up, test scores go down. • The researcher concludes that watching television can cause a person to be less intelligent. • PROBLEM: too many unknown variables!

15. Points of Validity to Consider • Researcher bias • This occurs when the researcher sees what he or she is looking for • . The expectations of the researcher will affect the findings. • To stop, use a double blind study – Participants will not be told if they are in the control or test group, and the experimenter is not told of the groups or the aim. • Participant bias • When the participant gives answers that they think the researcher wants to hear (Hawthorne effect) • To stop this, researchers may use a blind study: participants do not know what the study is about • Participant variability • If the researcher does not gather a stratified sampling, the results may only reflect the results of one particular gender or ethnic group • This can be controlled by selecting a random sample.

16. Validity and Reliability • Ecological validity– does the study represent what happens in real life? • If the research was conducted in a laboratory, the findings do not represent what participants would do in real life. It lacks ecological validity • Cross-Cultural validity – is the research relevant to other cultures or it is ethnocentric – based on the values and beliefs of only 1 culture • Participants should not be from just one culture or background • When applicable, researchers should also gather male and female participants

17. A Reliable study • A reliable study has results that can be replicated. • When another researchers conducts the experiment, they should get the same results

18. Activity • Give an example of each type of experiment • Laboratory: • Field: • Natural: • Correlation: