RESEARCH METHODS

Psychology Chapter 2

Goals of Psychology

• Describe

• Explain

• Predict

• Control

………behavior and mental processes

Critical Thinking

1. Thinking that does not blindly accept arguments or conclusions but questions their validity

The opposite is NOT THINKING (willingly accepting the most simple explanation).

Why is Research Important?

Research and Research Methodology

1. Method of asking questions then drawing logical supported conclusions based on facts

2. Researchers need to be able to determine if their conclusions are reasonable or not (critical thinking).

Scientific Method

1. Technique using tools such as observation, experimentation, and statistical analysis to learn about the world

2. Through its use, psychology is thereby considered a science.

Steps to the Scientific Method1. Form a research question

2. Develop a hypothesis

3. Test hypothesis

4. Analyze data / results

5. Draw a conclusion

6. Report results– Publication– Replication

Theory1. Tentative explanation for observed

findings– Uses results from individual studies – Tool for explaining observed behavior

2. Theories can change as new scientific evidence is found.

3. Analogy: Prosecuting Attorney presents their theory backed up by evidence to the jury.

Common Sense

1. Conclusions based solely on personal experience and sensible logic

2. Most of the time it is good but…can lead to incorrect conclusions

Did You Know…

• It is nearly impossible to fold a regular sheet of paper in half more than 8 times.

• Go ahead and try!

• Mythbusters pulled it off with a piece of paper as big as an airplane hanger and a steam roller.

Science vs. Common Sense1. Science helps build explanations that

are consistent and predictive as opposed to conflicting and describing the past (hindsight)

2. Science is based on– knowledge of facts– developing theories – testing hypotheses– public and repeatable procedures

Hindsight Bias1. The tendency to exaggerate one’s ability to have foreseen

how something would turn out after learning the outcome.

2. The “I knew it all along” phenomenon.– Week before the 1985 Super Bowl, 81% of students in a Stanford

Psychology class predicted the Miami Dolphins would win. 40% said the Dolphins would win by 10 or more points.

– A week after San Francisco 49ers decisive victory, he asked the group who picked the 49ers.

• 58% said they picked the 49ers

• NO ONE remembered saying the Dolphins would win by at least 10 points.

Overconfidence1. Tendency to overestimate the accuracy of our

current knowledge2. We are more confident than we are correct.

3. Overconfidence in ourselves can lead us to say dumb things:– “Man will never reach the moon, regardless of all

future scientific advances.” - Lee DeForest, inventor of vacuum tube, 1957

REVIEW QUESTIONWhat is the difference between Common Sense and Science?

ANSWER:

Common sense relies on the past and may be wrong.

Science uses facts to provide consistent predictions

DO YOU AGREE OR DISAGREE?

BiasA Researcher’s Worst Enemy

WHY????

Bias

1. Situation in which a factor unfairly increases the likelihood of a researcher reaching a particular conclusion

2. Bias should be minimized as much as possible in research

Confirmation Bias

• Our tendency to search for information that confirms our beliefs and ignore those that don’t.

Researcher Bias

• The tendency to notice evidence which supports one particular point of view or hypothesis

Volunteer Bias• People who volunteer to participate in a survey

differ from those who do not.• Those who complete it are often willing to share,

have similar interests, have spare time (magazine surveys).

• These factors skew or slant the results.

• Eliminate this by using a random sample where everyone has equal chance of being chosen to participate.

Participant Bias• Tendency of research subjects to respond in

certain ways because they know they are being observed– Do you act the same in the classroom as you do at

home?

• The subjects might try to behave in ways they believe the researcher wants them to behave

• Can be reduced by naturalistic observation

Research Strategies

Surveys

Observations

Experiments

Research Strategies Fall Into 2 Categories

• Descriptive—strategies for observing and describing behavior– Observation– Surveys

• Experimental—strategies for inferring cause and effect relationships among variables

Example from August 9Question: Can we make any

determinations about these scores?

• 2nd Period survey on “what you know about psychology”

• Average: 45.78• Low= 28• High= 59

• 4th Period survey on “what you know about psychology”

• Average: 46.50• Low= 21• High=57

Longitudinal and Cross-Sectional

Studies

Developmental Psychologists• Psychologists who study how

individuals change throughout their lifetime

• These psychologists use longitudinal & cross-sectional studies

Longitudinal Study

• Researchers study the same group of individuals for many years to see how they change.

• Can be very expensive and difficult to conduct

• Risky – people may drop out

Cross-Sectional Study

• Researchers simultaneously study a number of subjects from different age groups and then compare the results to see how they are different.

• Cheaper, easier than longitudinal studies, but group differences may be due to factors other than development. (More variables.)

Longitudinal/Cross Sectional Study

Naturalistic Observation

• Method of observation where subjects are observed in their “natural” environment

• Subjects are not aware they are being watched – researcher does not interfere

• Could use hidden cameras or two way mirrors

• Ex: People eating in a restaurant

Laboratory Observation• Not always a sterile room.

• Place where the environment can be controlled to minimize the number of variables.

• Negatives are that it may cause the subject to act differently than it normally would.

• Ex: Skinner Box, maze, fish tank

Case Study• In depth study of one individual with the hopes of

determining universal principles• Generally used to investigate rare, unusual, or extreme

conditions– Example: Phineas Gage

Negatives:• This technique is very open to bias• Difficulty of applying data from one person to

everyone

Survey Method

• Research method that relies on self-reports; uses surveys, questionnaires, interviews.

• Usually a very efficient and inexpensive method

• Can you guess some limitations of this method of research?

Survey Limitations

• Accuracy is a concern; people are not always honest.

• They fear confidentiality or want to please the researcher.

• Example: Tooth brushing survey in 1960s. If as many people actually brushed their teeth as often as they claimed to brush their teeth, 33% (?) more toothpaste would have been sold that year.

Sampling Terms• (Target) Population—large (potentially infinite)

group represented by the sample. Findings are generalized to this group.

• Sample—selected segment of the population for the study

• Stratified or Representative sample—closely parallels the target population on relevant characteristics; sample is proportional to TARGET POPULATION

• Random selection—every member of larger group has equal chance of being selected for the study sample

Random Sample

• A sample that represents the target population:– Each member of the population has an equal

chance of being included.– If a sample is not random it is said to be

biased.– Increase chances of representing population

when sample is BIG ENOUGH– How would you pick a random sample???

Generalizing the Results

• Applying the findings from the research group to other groups.

• Be cautious about generalizing when it isn’t a random or stratified sample.

• Example: Car preference differs between men, women, region, socio-economic background, and more.

Correlational Study• Examine the relationship of how closely one

thing is related to another • Collects a set of facts organized into two or more

categories– measure parents’ disciplinary style– measure children’s behavior

• Correlation reveals relationships among facts– e.g., more democratic parents have children who behave better

• Correlational studies are helpful in making predictions.

Correlational Study

• Does NOT determine a cause and effect relationship between the variables

• Correlation CANNOT prove causation

– Do democratic parents produce better behaved children?

– Do better behaved children encourage parents to be democratic?

• May be an unmeasured common factor

– e.g., good neighborhoods produce democratic adults and well-behaved children

• Does NOT determine why the two variables are related--just that they are related.

Zero Correlation

• There is no relationship at all between the two variables.

How to Read a Correlation

Correlation & Causation

• There is a strong +.90 correlation in shoe size and IQ.

• Does this mean that a large shoe size is the cause for higher intelligence?

• What else could explain this?

•YOUR FEET GROW AS YOU GET OLDER & WISER

Let’s Review

Experimental Method

The Only Way to Show

Cause & Effect

Experimental Terms

1. Variable – part of experiment that changes2. Independent Variable (IV)– controlled by

researcher. This variable causes something to happen.

3. Dependent Variable (DV) – watched by the researcher to see the impact of the IV. This variable is the effect that is caused by the IV.

Groups1. Experimental group – receives the treatment;

frequently a drug

2. Control group – receives no treatment; usually receives a placebo (fake drug)

3. “Placebo Effect” – participants react because they THINK they are receiving treatment (sugar pill)

– Mind over Matter

4. “Nocebo” – If told a drug won’t work, the person will feel it doesn’t work even if it is a legitimate drug.

Eliminating Bias

• Single Blind Study – Participants do not know if they are receiving the treatment of the placebo

• Double Blind Study – Neither the participants nor the researchers know if they are administering the treatment or the placebo.

Limitations of Experiments

• Conditions in an experiment may not reflect conditions of real life.

• (Must simplify variables to get useful information.)

• Ethical considerations in creating some more “real life” situations

Research Ethics

• Confidentiality – participants are more likely to be truthful if they know their privacy is protected. Confidentiality can be broken if information reveals harm to another person

Ethics

• Informed consent – some studies may have long term threats or irreversible effects. – Participants must be given a choice to participate after

being informed of the study.

• Deception— is allowable when benefit outweighs harm and participants receive full explanation at its conclusion

Animal Research• APA has rules for animals, too.

• Often used instead of humans when topic could not be ethically studied on a human.– Ex: Early separation studied by Harlow in 1959 with

monkeys.

• Animal experiments lead to solutions with humans – eating disorders, drug treatments

• Still controversial due to the fact that animals can be harmed in studies.