1 Research Methods Unit 2. 2 Hindsight Bias is the “I-knew-it-all-along” phenomenon. After learning the outcome of an event, many people believe they.

1

Research Methods

Unit 2

2

Hindsight Bias is the “I-knew-it-all-along” phenomenon.

After learning the outcome of an event, many people believe they could have

predicted that very outcome.

Hindsight Bias

3

OverconfidenceWe tend to think we know more than we do.

82% of U.S. drivers consider themselves to be in the top 30% of

their group in terms of safety

81% of new business owners felt they had an excellent chance of their businesses succeeding. When asked about the success of their peers, the answer was only 39%. (Now that's

overconfidence!!!)

The Barnum Effect

It is the tendency for people to accept very general or vague characterizations of themselves and take them to be accurate.

5

The Scientific Attitude

The scientific attitude is composed of curiosity (passion for exploration), skepticism

(doubting and questioning) and humility (ability to accept responsibility when wrong).

6

Scientific Method

Psychologists, like all scientists, use the scientific method to construct

theories that organize, summarize and simplify observations.

Applied V. Basic Research• Applied Research

has clear, practical applications.

• YOU CAN USE IT!!!

• Basic Research explores questions that you may be curious about, but not intended to be immediately used.

Research on therapies for drug addicts has a clear purpose.

Studying how kissing changes when you get older is interesting…but that’s about it.

8

Scientific Method

1. Observe some aspect of the universe.

2. Invent a theory that is consistent with what you have observed.

3. Use the theory to make predictions.

4. Test those predictions by experiments or further observations.

5. Modify the theory in the light of your results.

6. Go to step 3.

9

A Theory is an explanation that integrates principles and

organizes and predicts behavior or events.

For example, low self-esteem contributes to depression.

Theory

10

A Hypothesis is a testable prediction, often prompted by a theory, to enable

us to accept, reject or revise the theory.

People with low self-esteem are apt to feel more depressed.

•All hypothesis’s must have operational definitions & be replicable.

Hypothesis

Null Hypothesis

• the hypothesis the researcher tries to disprove.

• The researcher never proves or accepts the null hypothesis, but can only reject it or not reject itExample:Hypothesis: Roses exhibit greater rate of growth when planted in soil rather than compost. Null Hypothesis: Roses do not exhibit greater rate of growth when planted in soil rather than compost. 

• 2nd example….You might see it written like this:

H1: Gender has an effect on spatial ability

H0: Gender does not have an effect on spatial ability

11

Operational Definitions

• precise statements of the procedures (operations) used to define the variables

• Example– Anxiety is a concept that most of us are all too

familiar with. It is an unpleasant feeling that occurs in certain situations. It can disrupt our functioning if it is excessive, but it also motivates behavior. So how do you measure it? How do you operationally define anxiety?

12

Operational definitions continued

• Since this is a concept that we have first-hand knowledge of, we might start the process of operationally defining anxiety by asking ourselves what it is like. What do we feel? How do we react? How do others react? What features in other people would suggest to us that they are anxious? 

– Self reported answers – Physiological arousal (heart beating fast, sweating, shaking, trembling, nervous

stomach, stomach ache, accelerated breathing, rise in temperature, decrease in temperature, etc…)

Lets try coming up with a few

A psychologist wants to know if his new form of psychotherapy will make people less depressed.

College athletes are not as smart as regular students. The teacher wants to find a way to help make Billy act more

friendly toward the other children13

Replicate (Replication)

• repeating the essence of a research study, usually with different participants in different situations, to see whether the basic finding extends to other participants and circumstances

• Doing it again to see if you get the same results

14

15

Descriptive Research• Any research that observes and records.• Does not talk about relationships, it just

describes the situation

What is going on in this picture?

We cannot say exactly, but we can describe what we see.

Thus we have…..

16

Types of Descriptive Research

• Case Study Method

• Survey Method

• Naturalistic Observation Method

17

Case Study

A technique in which one person is studied in depth to reveal underlying behavioral principles.

https://abdullaman.wordpress.com/2011/05/01/five-landmark-psychology-case-studies-you-should-know-about/

18

Clinical Case Studyis a form of case study in

which the therapist investigates the problems associated with a client.

You cannot apply what you learn from a case study to

the entire population.

http://behavioralhealth.typepad.com

19

Survey

A technique for ascertaining the self-reported attitudes, opinions or behaviors of people usually done by questioning a

representative, random sample of people.

http://ww

w.lynnefeatherstone.org

20

The Survey Method

• Used in both descriptional and correlational research.

• Use Interview, mail, phone, internet etc…

• The Good- cheap, anonymous, diverse population, and easy to get random sampling (a sampling that represents your population you want to study).

21

Survey Method: The Bad

• Low Response Rate

• People Lie or just misinterpret themselves.

• Wording Effects

How accurate would a survey be about the frequency of diarrhea?

22

Wording Effect or Framing

Wording can change the results of a survey.

Q1: Should nude ads be allowed on TV? Or

Q2: Should nude ads be forbidden on TV?

The second question adds a value judgement and can sway the way people think

23

If each member of a population has an equal chance of inclusion into a sample, it is called a

random sample (unbiased). If the survey

sample is biased, its results are not valid.

The fastest way to know about the marble color ratio is to blindly transfer a few into a smaller jar and count them.

Random Sampling

24

Why do we sample?

• One reason is the avoid the False Consensus Effect: The tendency to overestimate the extent to which others share our beliefs and behaviors.

Population

• All the possible people or cases within a specific group– Example:

• I want to know what students of at SMHS think about the food in the cafeteria

– My population is every single student at SMHS

» There is NO way I’m going to be able to get to survey EVERY student, so I would take a RANDOM SAMPLE

» I’d pass out surveys during all the lunches to each student that walked into the cafeteria on a given day.

» Those students that returned the survey are now part of my sample

25

26

Naturalistic Observation

• Observing and recording behavior in natural environment.

• No control- just an observer.

What are the benefits and detriments of Naturalistic Observation?What did Jane Goodall do?

27

Correlational Research• Detects relationships between variables.• Does NOT say that one variable causes

another. (Correlation DOES NOT EQUAL

CAUSATION) Did you know that there is a relationship between ice cream sales and murder rates. Does that mean that people who buy ice cream are murders? Or that eating ice cream causes you to murder someone?

28

Correlation

When one trait or behavior accompanies another, we say the two correlate.

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 the relationship between two

variables.

29

Scatterplot is a graph comprised of

points that are generated by values

of two variables. The slope of the

points depicts the direction, while the amount of scatter

depicts the strength of the relationship.

Scatterplots

Line of best fit or regression line is the smooth line that reflects the general pattern in a graph. You can draw a line through each dot

30

Positive correlationAs one variable goes up the other goes up or as one goes down the other goes downYou can look at the correlational coefficient to see if there is a positive sign (+) after the r =

Negative correlationAs one variable goes up the other goes down You can look at the correlational coefficient to see if there is a negative sign (-) after the r =

Scatterplots

Example Scatterplot

The scatterplot below shows the relationship between height and temperament in people.

r= +0.63

32

Illusory Correlation

The perception of a relationship where no relationship actually exists. Parents conceive

children after adoption.

Confirming evidence

Disconfirming evidence

Do not

adopt

Disconfirming evidence

Confirming evidence

Adopt

Do not conceiveConceive

Michael N

ewm

an Jr./ Photo Edit

The Experiment

• Only research method capable of showing cause and effect

34

Experimental Research

• Explores cause and effect relationships.

Eating too many bananas causes Constipation

The 1st few steps of an experiment

• You have your question & your hypothesis• Pick your population• You have to randomly sample individuals from

your population• Your sample must be a representative sample

– a sample that accurately reflects the characteristics of the population as a whole

35

Stratified sampling

• a process or selecting individuals from a population in such a way that the subgroups in the population are represented in the sample, the population is divided into subpopulations and random samples are taken of each stratum.– At SMHS we have a very diverse population

so I would need to make sure each subgroup is represented in my sample.

Now you have your participants for your experiment. What do you do next?

36

Random Assignment

• Assigning participants to one of the condition groups in such a way that all participants have equal chance of being chosen.

37

Groups (must be randomly assigned)

Experimental group

• Group that has the experiment done on them

• Receives the Independent variable (IV)– The variable the

experimenter manipulates

Control Group

• Group that DOES NOT have the experiment done on them

• Does NOT receive the independent variable

38

Variables• Independent Variable (I.V.): what is

manipulated by experimenter– The effect of the independent variable

is the focus of the study. • Dependent Variable (D.V.): What is

MEASURED or influenced by the independent variable

• Confounding/Extraneous variables– Other variables that can effect the outcome

of the experiment or study that were not controlled for or can not be controlled

40

When examining the effects of breast feeding upon intelligence

Breast feeding is the independent variableIntelligence is the dependent variableAre there other variables that effect

intelligence? Those would be confounding or extraneous variables

Example

Control Measures• Single-Blind: subjects are unaware of their

assignment group

• Double-Blind: subject and experimenter unaware of placement– Best to use to avoid experimenter and

participant bias

42

More Control MeasuresPlacebo: inert substance that is in place of IV in Control Group.

Placebo effect: results caused by expectations alone; any effect on behavior caused by the administration of an inert substance or condition

Hawthorne Effect• But even the

control group may experience changes.

• Just the fact that you know you are in an experiment can cause change.

Whether the lights were brighter or dimmer, production went up in the Hawthorne electric plant.

Other Research Method

Ex Post Facto (after the fact) • Research in which we choose subjects based on a pre-

existing condition like race or gender• Not a true independent variable• No cause and effect• Often used due to ethical concerns• Describes differences between groups of participants

that differ naturally

Flaws in Research happen• Sampling Bias• Overgeneralization• Placebo effect• Hawthorne & Barnum effect• Demand Characteristics

– a subtle cue that makes participants aware of what the experimenter expects to find or how participants are expected to behave. Can change the outcome of an experiment because participants will often alter their behavior to conform to the experimenters expectations

• Experimenter Bias

46

ComparisonBelow is a comparison of different

research methods.

Evaluating Research

You need to know the STRENGTHS AND WEAKNESSES of each of the following:

Experiment

Correlation

Surveys

Naturalistic Observation

Case Studies

Descriptive Statistics

• Just describes sets of data

• You might create a – frequency distribution– frequency polygons – Histogram

Measures of Central Tendency

• Mean – average score• Mode – most reoccurring score• Median – middle score

$25,000- cashier $25,000- stock room$25,000- assistant manager$100,000- manager$100,000- manager$200,000- regional manager$300,000- owner

To calculate the mean: Add up all the salaries ($775,000) and divide by the number of people (7).To calculate the median, I put all the scores in order (See above).

Let’s look at the salaries of the employees at one company

• The mean salary is about $110,000 so I can say the mean salary is $110,000 (I pay my employees very well). But is that really the case?

• The median salary looks good at $100,000.

• But the mode salary is only $25,000.

Maybe my data shows that my company is not the best place to work.

The Normal Curve

50

51

Skewed Distributions

• Negatively Skewed– When a distribution

includes extreme scores that are unusually high

• Positively Skewed – When a distribution

includes extreme scores that are low

52

Skewed Scores

• Positively skewed

• Negatively skewed

53

Measures of Variation• Range:

– distance between the highest and lowest scores

• Variance: – the degree to which a set of values varies from the mean of

the set of values

• Standard Deviation: – average amount by which the scores in a distribution deviate

around the mean. 

• Z-scores: – tells you how far the raw score is away from the mean in

terms of standard deviation units

Standard Deviation: the variance of scores around the mean.•The higher the variance or SD, the more spread out the distribution is.•Do scientists want a big or small SD?

Shaq and Kobe may both score 30 points per game (same mean).But their SDs are very different.

56

Standard Deviation

Scores

• A unit that measures the distance of one score from the mean.

• A positive z score means a number above the mean.

• A negative z score means a number below the mean.

58

Inferential StatisticsInferential Statistics• Interpret data and draw conclusions• Used to test validity of hypothesis (t-test)• Determine whether or not findings can be applied to the

larger population from which the sample was selected– Making sure the results are not due to sampling error and

chance

Sampling error• the extent to which a sample differs from the population

59

When sample averages are reliable and the difference between them is relatively large, we say the difference has statistical significance or is statistically significant.

For psychologists this difference is measured through alpha level (ᾁ) set at .05% or 1%

5% (p<.05) or 1% (p<.01) level of significance

When is a Difference Significant?

Statistical Significance

If the results are statistically significant•The difference is NOT due to Chance

• Meaning the manipulation of the IV created a change in the DV

•If the results were NOT statistically significant• then the results WERE due to chance and the

manipulation of the IV did not cause a change in the DV

60

Ethical Guidelines for Research

• APA -• IRB- Institutional

Review Board• Rules for both

humans and animals.

APA Ethical Guidelines for Human Research

All research goes before an institution review board (IRB) for approvalResearch involving humans must meet the following standards:

1. Coercion-participants cannot be forced in any way to participate in the study

2. Informed Consent-participants must know that they are involved in research and give their consent or permission

3. Anonymity/Confidentiality -the identities and actions of participants must not be revealed in anyway by the researcher

4. Risk -participants cannot be placed at significant mental or physical risk. DO NO HARM

5. Debriefing -participants must be told of the purpose of the study and provided with ways to contact the researchers about the results after the study is complete

Deception-if the participants are deceived in any way about the nature of the study the participants must be debriefed after the study is over

 62

Ethics for Animal Research

• Clear scientific purpose• Treated & cared for in

a humane way• Acquire animals legally• Least amount of

suffering possible…Do No Harm

• A trained psychologist must supervise all research with animals