Ms. Carmelitano

RESEARCH METHODSEXPERIMENTAL

STUDIES

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.”

BELL RINGER

Aim: The reason why the study is doneIndependent Variable: the variable that

the researcher manipulates Dependent Variable: the variable that is

measured after manipulationControl: A group that does not receive

the new treatment being studied and which is compared to the group that does receive the new treatment

STUDY VOCABULARY

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.

PRACTICE

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.

OPERATIONALIZED VARIABLES

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: MusicDependant Variable: ScoreOperationalized 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

EXAMPLE

Experimental hypothesis predicts the relationship between the independent and dependent variables H1

Null hypothesis: states independent variable will have no eff ect 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

HYPOTHESIS

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 H 1: 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 H 0: 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.

EXAMPLE

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

DIFFERENT TYPES OF EXPERIMENTS

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

LABORATORY 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

subwayPro:

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

FIELD 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

NATURAL EXPERIMENT

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 decreasesPros

The researcher is able to conduct research on variables that are diffi cult 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

CORRELATION STUDY

A researcher wants to understand if a child’s performance in school can be aff ected 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!

CORRELATION EXAMPLE:

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.

POINTS OF VALIDITY TO CONSIDER

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

A RELIABLE STUDY

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

Give an example of each type of experimentLaboratory:

Field:

Natural:

Correlation:

ACTIVITY