Research in PsychologyResearch in Psychology

AgendaAgenda

1. Bell Ringer: The Molly Case? (10)

2. Lecture: Research Methods (20)

3. Handout 1-11 and Discussion. (15)

4. M&M Activity, Sampling BB#2 (20)

5. Finish Case Study from yesterday5. Finish Case Study from yesterday

Objective

By the end of this lesson you will be able to identify the research methods of Psychology.

You will be able to define research terms.

Why do we need research?

Intuition and Critical ThinkingIntuition and Critical Thinking Human Intuition is highly limited. Critically thinking rarely comes easily to us!

– Critical Thinking: thinking that does not blindly accept arguments and conclusions

»examines assumptions

»discerns hidden values

»evaluates evidence

»An awareness to our own vulnerability

Hindsight biasHindsight bias – “I knew it all along” – “I knew it all along” phenomenon where after learning an phenomenon where after learning an outcome, one believes s/he could have outcome, one believes s/he could have predicted that very outcomepredicted that very outcome

Overconfidence Overconfidence – we think we know – we think we know more than we actually knowmore than we actually know

This is why we need psychological This is why we need psychological science.science.

Natural Observation -Natural Observation - Systematic Systematic study of behavior in a natural settingstudy of behavior in a natural setting

Description:– Careful observation of humans or animals in

real-life situations

Strength: – provides descriptions of behavior

Weakness:– DOES NOT explain how or why the behavior

occurs – only describes it

Example: Jane Goodall’s research was naturalistic observation

Case Studies

Description: detailed information gathered over time on a specific individual

Strength: provides descriptive data over a period of time and analyzes new phenomena

Weakness: emotional attachment or personal prejudice to subject can effect objectivity

Example:

Studying patients with gunshot wounds to the head over a period of years to see how injuries changed their behavior.

SurveySurvey Description: a technique for gathering the self-Description: a technique for gathering the self-reported attitudes, opinions, or behaviors of reported attitudes, opinions, or behaviors of peoplepeople

StrengthsStrengths::

1.1.    easy administration, scoring, and statistical easy administration, scoring, and statistical analysis. analysis.

   WeaknessesWeaknesses::

1.1.    people lie or are opinionated people lie or are opinionated

2.2.    groups should be representative or data is groups should be representative or data is skewedskewed

3. wording of question can sway answers3. wording of question can sway answers

ExampleExample::– Survey students about their opinions on Survey students about their opinions on

homeworkhomework

Sampling when doing studies:Sampling when doing studies:

Representative samples are necessary Representative samples are necessary because you can’t survey because you can’t survey everyoneeveryone in a in a given population.given population.

Thus you create a Thus you create a random sample random sample that that fairly represents a population. (Every person fairly represents a population. (Every person in a group has an in a group has an equal equal chance to chance to participate)participate)

Ex. Ex. You want to survey the school You want to survey the school about attitudes on HW. By using a about attitudes on HW. By using a students list where everyone is students list where everyone is numbered, you pick as many as numbered, you pick as many as possible to participate. possible to participate.

The bigger the sample the better – as The bigger the sample the better – as long as it is long as it is representative. representative.

M&M Activity M&M Activity

No, you may not No, you may not eat your candy. eat your candy. This is an This is an experiment.experiment.

All the packages together make up All the packages together make up the _________ from which we are the _________ from which we are getting the ___________________, getting the ___________________, which is each individual package.which is each individual package.

Each student who selected a pack of Each student who selected a pack of M&M’s have selected a M&M’s have selected a _______________._______________.

Separate the colors on the desk.Separate the colors on the desk.

populatiopopulationnrepresentative representative samplesample

random random samplesample

You should have according You should have according the the Mars company,the the Mars company,

30% brown30% brown 20% red20% red 20% yellow20% yellow 10% green10% green 10% orange10% orange with a total of 24 M&M’s in a pack.with a total of 24 M&M’s in a pack.

Correlational Method Description: Used to look at relationships

between two variables.

Strengths: The stronger the correlation the more successfully one variable can be predicted from the other

Weaknesses: Does not est. cause and effect. Often a 3rd (an intervening variable) involved

Example There is a positive

correlation showing that people who go to college will have higher incomes.

an increase in one variable tends to be associated with an increase in the other

Example 2 If an increase in one variable

tends to be associated with a decrease in the other then this is known as a negative correlation

There is a negative correlation showing that the more education a person has the LESS likely the are to be racist

Correlation and CausationCorrelation and Causation

ScatterplotScatterplot A graph comprised of points that are A graph comprised of points that are

generated by values of generated by values of two variablestwo variables..

The The slopeslope of the points depict the direction, of the points depict the direction, while the amount of scatter depicts the while the amount of scatter depicts the strength of the relationship.strength of the relationship.

Correlational coefficientCorrelational coefficient: a statistical : a statistical measure of the degree of relatedness or measure of the degree of relatedness or association between two sets of data that association between two sets of data that ranges from -1 to 1.ranges from -1 to 1.

Perfect Perfect positive positive correlationcorrelation

Perfect Perfect negative negative correlatiocorrelationn

No No relationshirelationshipp

What is the relationship between What is the relationship between height and temperament shown in height and temperament shown in

the scatterplot below?the scatterplot below?

It shows a moderate positive correlation. It shows a moderate positive correlation. +0.63+0.63

Experimental MethodExperimental Method

Description: researcher manipulates a variable under controlled conditions and observes a response

Strengths: Can establish cause and effect relationships. Experiments should be able to be replicated in order to be found valid and reliable.

Weakness: Because it is done under controlled conditions hard to apply to real world situation

Other types of studiesOther types of studies

Longitudinal studyLongitudinal study – study one person – study one person or event over a long period of timeor event over a long period of time

Ex-post facto study – Ex-post facto study – study something study something after it happened naturally – look at after it happened naturally – look at effect – seek causeeffect – seek cause

Statistics Measures of central tendency – typical

scores

– Mean – average of scores

– Median: middle score in a rank distribution

– Mode: most frequent score

Statistical procedures analyze and interpret analyze and interpret data allowing us to see what the unaided eye misses.

Researchers are looking for statistical statistical significancesignificance

Measures of VariationMeasures of Variation Range – Range – difference between the difference between the

highest and lowest scores in a highest and lowest scores in a distributiondistribution

Standard deviation – a computed Standard deviation – a computed measure of how much measure of how much scores vary scores vary around the mean (around the mean (BELL CURVEBELL CURVE))

A skewed distributionA skewed distribution

ClosureClosure

Directions: For each of the following hypotheses, explain which research method would be best and why that method is best.

If a cancer patient receives chemotherapy, then they will live longer than a cancer patient who does not.

Do people think coffee helps performance at work? 

How does playing a high school sport effect amount of friends you have?

If there are no cars around, then most people do not completely stop at a stop sign

If students study more, then they will do better on tests.

What percentage of students actually use the bathroom when they ask to go to the bathroom?

Students behave differently around teachers.

How does laser eye surgery effect vision later in life?