research in psychology

Research in Psychology

Unit 1: Modules 2 & 3

AP Psychology

Jessica Mulder

The Limits of Common Sense

• We cannot always rely on our intuition and common sense to tell us what is true about the world.

The earth is flat!

The sun revolves around the earth!

How can we think that “opposites attract” & “birds of a feather flock together”?

Try ThisIf you drop a bullet off a

table three feet high, and fire another one straight across an empty football field, which hits the ground first?

QuickTime™ and a decompressor

are needed to see this picture.

How do we come up with the truth?

1. Ask Questions!

2. Think Critically- Have a Scientific Attitude

3. Use a systematic method to find out the answers to your questions. - The Scientific Method!



The Scientific Method

• The scientific method is a process for experimentation that is used to explore observations and answer questions.

• Scientists use the scientific method to search for cause and effect relationships in nature.



The scientific method starts when you ask a question about something that you observe: How, What, When, Who, Which, Why, or Where?

Rather than starting from scratch, you want to be a savvy psychologist using library and Internet research to help you find the best way to do things and insure that you don't repeat mistakes from the past.

A hypothesis is an educated guess about how things work:"If _____[I do this] _____, then _____[this]_____ will happen."

You must state your hypothesis in a way that you can easily measure.

Your experiment tests whether your hypothesis is true or false. There are many ways to test a hypothesis! Experimentation is just ONE way

Once your experiment is complete, you collect your data and analyze them to see if your hypothesis is true or false.

Once your experiment is complete, you collect your measurements and analyze them to see if your hypothesis is true or false.

The Scientific Method is great

but…• Experimenter / Research Bias– Report Research allow for replication– Use Operational Definitions – Be transparent in research!

• ALWAYS QUESTION!

• ALWAYS remain both critical AND open minded.

Ethics• The rules of conduct recognized in respect to

a particular group.• APA (American Psychological Association)

• Ethical considerations are a major component in research design.

• Any type of academic research must first propose the study to the ethics board or institutional review board (IRB) at the institution

Ethics for Research: Animal

Studies1. They must have a clear scientific purpose. The research must answer a specific, important scientific question.Animals chosen must be best-suited to answer the question at hand.

2. They must care for and house animals in a humane way.


Studies

3. They must acquire animal subjects legally. Animals must be purchased from accredited companies. If wild animals must be used, they need to be trapped in a humane manner.

4. They must design experimental procedures that employ the least amount of suffering feasible.


Studies



1. Participation must be voluntary.

Ethics for Research: Human

Studies2. Informed consent- Participants must know that they

are involved in research and give their consent.

3. Deception- Deception cannot be used unless it is absolutely necessary!

4. Anonymity/Confidentiality- Participants’ privacy must be protected. Their identities and actions must not be revealed by the researcher.


Studies

5. Risk- Participants cannot be placed at significant mental or physical risk.

6. Participants must be debriefed (told the purpose of the study) and provided with ways to contact the researchers about study results. When research involves deception, it is particularly important to conduct a thorough debriefing.


Studies

Research Methods• Case Studies

• Surveys

• Naturalistic Observation

• Longitudinal & Cross-sectional Studies

• Correlation

• Experimentation

Case Studies• An observational technique in which

one person is studied in depth in the hope of revealing universal principles.

Advantages DisadvantagesGood source of hypotheses.

Provides in-depth information on individuals.

Unusual cases can shed light on the situations or problems that are unethical or impractical to stud in other ways.

Vital information may be missing, making the case hard to interpret.

The individual may not be representative or typical (cannot generalize to general population)

Subject and research objectivity may be a problem.

Surveys• A technique for ascertaining the self-

reported attitudes or behaviors of people, usually by questioning a representative, random sample of people.

Advantages DisadvantagesProvides a large amount of information on large numbers of people.

Inexpensive.

If sample is non-representative or biased, it may be impossible to generalize from the results.

Responses may be inaccurate or untrue.

PopulationPopulation- all the cases in a group, from

which you want to study.

If you wanted to study the effectiveness of a new ACT prep program on CPS juniors, you population would be ALL CPS juniors.

It would be really difficult, time consuming, and expensive to evaluate every junior in CPS, so…

Random Sample…so you choose a random sample of the

population to test instead!

A random sample is a sample that fairly represents a population because each member has an equal chance of inclusion.

If we wanted accurate results on how our new ACT prep class helped CPS juniors, would it make sense just to give our survey to students on the North side? South side? Low SES? 16 year olds?

Naturalistic Observation

Observing and recording behavior in naturally occurring situations without trying to manipulate and control the situation.

Advantages DisadvantagesAllows description of behavior as it occurs in the natural environment.

Often useful in first stages of a research program.

Allows researcher little or no control of the situation.

Observations may be biased.

Does not allow firm conclusions about cause and effect.

Longitudinal and Cross-Sectional

StudiesCross-Sectional Study

– A research technique that compares individuals from different age groups at one time.

– More common. – Advantages: much more

efficient than longitudinal studies.

– Disadvantages: difficult to determine cause and effect, hard to control for differences between groups, cannot measure change.

Longitudinal Study– A research technique that

studies the same group of individuals over a long period of time.

– Tend to be rare.– Advantages: provide a rich

source of data.

– Disadvantages: expensive, time-consuming, difficult to

conduct, cohort effect.

Both methods are used mostly by developmental psychologists!

CorrelationA measure of the extent to which two

factors vary together.

How well does one thing predict the other?

Let’s look at test scores and time spent studying.

CorrelationTest scores and time spent studying do

seem to very together… but how much and how strongly?

Correlation coefficient

Indicates directionof relationship

(positive or negative)

Indicates strengthof relationship(0.00 to 1.00)

r = 0.37+

Correlation Coefficient is a statistical measure of relationship

between two variables.

Correlation

Perfect positivecorrelation (+1.00)

Perfect negativecorrelation (-1.00)

No relationship (0.00)

Scatter plots help to show both how strongly two variables are correlated AND the direction of the correlation.

Correlation

• Drinking and Driving Ability• Eating and Weight Gain• Height and Intelligence

• Low self esteem and Depression

CORRELATION does not equal CAUSATION!!

CorrelationAdvantages Disadvantages

Shows whether two or more variables are related.

Allows general predictions to be made.

Does not permit identification of cause and effect.

Must be careful not to form illusory correlations.

• An perceived nonexistent correlation is called an illusory correlation.

• When we believe there is a relationship between two things, we are likely to notice and recall instances that confirm our beliefs.

•Weather changes trigger arthritis pain, more people end up in the emergency room during a full moon.

ExperimentationA research method in which variables are

manipulated and measured to isolate cause and effect.

Advantages DisadvantagesAllows research to control the situation.

Permits researcher to identify cause and effect, and to distinguish placebo effects from treatment effects.

Situation is artificial, and results may not generalize well to the real world.

Sometimes difficult to avoid experimenter effects.

Experimentation is all about manipulating and controlling variables.

Experimentation

Independent Variable (IV)

Dependent Variable (DV)

The experimental factor that is being manipulated; the variable whose effect is being studied.

The variable that may change in response to manipulations of the IV; the variable that is being measured.

Independent and Dependent VariablesDr. Imanut wants to examine whether a new drug

increases the maze running performance of older rats. Dr. Imanut teaches two groups of older rats to find a piece of tasty rat chow in the maze. One group of rats is given the new drug while they are learning the maze. The second group is not given the drug. One week after having learned the maze he retests the rats and records how long it takes them to find the rat chow.

Independent and Dependent Variables1. Children’s reading skill is measured after taking

either a special reading class or a standard reading class.

2. College students’ memory for German vocabulary words is tested after a normal nights sleep or a night of no sleep.

3. Experiment title: “The effect of a daily walking program on elderly people’s lung capacity.”

4. People’s ability to avoid “accidents” in a driving simulator is tested before, during, and after talking on a cell phone.

Experimentation

Running an experiment:1. Identify a question and form a hypothesis.2. Define variables and make operational

definitions.3. Recruit participants and randomly assign

participants into the experimental or control group.

4. Conduct the experiment / collect data5. Analyze Data6. Reject or Accept the Hypothesis / Formulate

Conclusions

Research ?: Does Prozac reduce depression?

Placebo EffectExperimental results caused

by expectations alone.







Double-Blind ProcedureAn experimental procedure in which both

the research participants and the research staff are ignorant (blind) about whether the research participants have received the treatment or a placebo.

A method of control!

Random Assignment

• Assigning participants to either the experimental or control conditions by chance, thus minimizing preexisting differences between those assigned to the different groups.

• A form of control.

Experimental and Control Groups

Experimental Group Control Group

The condition of an experiment that exposes participants to the treatment.

Receives the IV.

The condition of the experiment that serves as a comparison for evaluating the effect of the treatment.

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