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RESEARCH METHODS AP Psychology Ms. Brown Myers – Ch. 1

Thinking Critically and Research Methods

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Thinking Critically and Research Methods. AP Psychology Myers, Ch. 1. Limits of Intuition and Common Sense. “The naked intellect is an extraordinarily inaccurate instrument.” - Madeleine L’Engle (1977). Why Science?. How can we best understand why people think, feel, and act as they do? - PowerPoint PPT Presentation

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Page 1: Thinking Critically and Research Methods

RESEARCH METHODS

AP PsychologyMs. Brown

Myers – Ch. 1

Page 2: Thinking Critically and Research Methods

LIMITS OF INTUITION &

COMMON SENSE“The naked intellect is an extraordinarily inaccurate

instrument.”

- Madeleine L’Engle (1977)

Page 3: Thinking Critically and Research Methods

Why Science?•How can we best understand why people think, feel, and act as they do?•Hunches?•Common sense?• Intuition?

•Psychology needs a scientific approach to separate “common sense” and “hunches” from actual credible evidence.•Differ from person to person•Not always 100% correct•Always seem correct after the fact

Page 4: Thinking Critically and Research Methods

Hindsight Bias•The tendency to believe, after learning an outcome, that one would have foreseen it.•“I knew it all along phenomenon”

•Hindsight is 20/20 – after the fact, it is easy to see why an event occurred, someone acted in a certain way, etc

•Psychological findings often seem already known or like common sense because we constantly observe psychological phenomena or “knew it all along.”

Page 5: Thinking Critically and Research Methods

Overconfidence•The tendency to overestimate our abilities, including knowledge (the illusion of knowledge)•Faster•Smarter•Stronger•More aware•More observant

•Even after being presented with evidence that contradicts previous assumptions about ourselves, most claim, “Well I was close.”

Page 6: Thinking Critically and Research Methods

Draw a bike.

C

B

D

A

Page 7: Thinking Critically and Research Methods

A I bet you were pretty confident you knew how to draw a bike…

Our brains allow us to be overconfident to shield us from everything we DON’T know – “the illusion of knowledge” effect.

How many of you are claiming, “I knew it all along!” (hindsight bias!)

Page 8: Thinking Critically and Research Methods

Lead to…

The Scientific Method•A method in which scientists make observations, form theories, and then refine theories in the light of observations.

1) Theories

2) Hypothesi

s

3) Research and

Observations

Lead to…

Generate

or refi

ne…

Theory - an explanation using an organizes data and predicts observations (NOT fact)

Hypothesis - a testable prediction, often implied by a theory

Replication – repeating the study to see if the basic finding extends to other participants in other circumstances

Page 9: Thinking Critically and Research Methods

DESCRIPTIVE METHODS

Description is the starting point of any science.

These types of research methods describe behaviors/attitudes, not explain them.

Page 10: Thinking Critically and Research Methods

Case Study•An observation technique in which one person is studied in depth with the hope of revealing universal principles.

•Pros: • Insight into specific cases that possibly could not be studied due to ethics

•Cons: • Individual studies are hard to generalize to large populations•Some events/circumstances cannot be replicated (ethics)

•Ex: brain lesion studies, instances of socially isolated (“feral”) children

Page 11: Thinking Critically and Research Methods

Survey•A technique for ascertaining the self-reported attitudes or behaviors of people, usually by questioning a representative, random sample of them.

•Must have a representative and random sampling from the population for generalization to be possible•Population – all of the cases in a group from which samples may be drawn for study

•Representative – reflective of the population•Random sample – a sample in which all individuals have an equal chance of inclusion in the study

•Generalization – the ability to reflect results from the random sample on the entire population

Page 12: Thinking Critically and Research Methods

Survey•Pros:

•Can study large populations from a representative sample

•Cons:•Self-reporting is not always reliable

• Social-desirability effect – the tendency of respondents to answer questions in a manner that will be viewed favorably by others.

•Samples are not always representative•Results are largely based on how questions are worded (“aid to the needy” instead of “welfare”)

•Ex: Gallup polls, Kinsey Report on sexuality

Page 13: Thinking Critically and Research Methods

Naturalistic Observation•Observing and recording behavior in naturally occurring situations without trying to manipulate and control the situation. •The observer must not manipulate or stage the situation.

•Pros:•Observe people/animals in real, not artificial, environments

•Cons:•No control over events or variables

•Ex: videotaping mothers and children together in different cultures, recording students’ self-seating patterns in the lunchroom

Page 14: Thinking Critically and Research Methods

CORRELATIONAL METHODS

Describing behavior is the first step to predicting it.When observed variables seem to relate to each other,

it is said they correlate.

Page 15: Thinking Critically and Research Methods

Correlational Research•A measure of the extent to which two factors vary together, and thus of how well either factor predicts the other.•How are two things related?•How strong is this relationship?•Can the relationship shape predictions?

•Scatterplots – a graphed cluster of dots, each of which represents the values of two variables. The amount of scatter suggests the strength of the correlation (little scatter = more correlation)

Page 16: Thinking Critically and Research Methods

Positive Correlation•Two variables rise or fall together•The taller you are, the more you weigh

•The more you smoke, your risk of cancer increases

•As temperature rises, crime rate increases

•As the ocean level decreases, the fish population decreases

Page 17: Thinking Critically and Research Methods

Negative Correlation•Two variables relate inversely to each other – as one rises, the other falls.•The more you brush your teeth, your risk of cavities decreases

•The more years spent in jail, the lower the education level

•The more you hold a baby, the less it cries

•The more hours spent watching TV, the less time spent doing HW

Page 18: Thinking Critically and Research Methods

No Correlation•Two variables do not seem to be related•People born later in the year and intelligence level

Page 19: Thinking Critically and Research Methods

Correlation coefficient •The mathematical expression of the relationship, ranging from -1 to +1•Measures how well either one predicts the other and how strong that relationship/prediction is (0 = no relationship)

•r = +0.37• r correlation coefficient (relationship)• + indicates direction of relationship (positive or negative)• 0.37 Indicates strength of relationship (0.00 weak to 1.00 strong)

r = -1.00

r = +1.00

r = 0

Page 20: Thinking Critically and Research Methods

PracticePositive or Negative Correlation?• Those with higher rates of

depression tend to have higher risks of suicide.

• The louder the music while studying, the lower the exam performance.

• The more you observe aggression, the more aggression you display.

Strong , Moderate, or Weak Correlation?•+0.71

•Fairly strong relationship

•-0.13•Fairly weak relationship

•+0.46•Moderate relationship

Page 21: Thinking Critically and Research Methods

Could cause

OR

Could cause

OR

Could cause

Correlation IS NOT Causation

•Correlations cannot fully predict future behaviors/attitudes, regardless of how strong the correlation coefficient is.•Ex: low self esteem is correlated with depression, however this does not mean that low self-esteem directly causes depression.

(1) Low self esteem

(2) Depression

(3) Distressing events or biological predisposition

Depression

Low self esteem

Depression

Low self esteem

Page 22: Thinking Critically and Research Methods

Correlational Research•Pros:

•Can measure the extent of a relationship

•Cons:•Correlation is not causation (just because two things are related does not mean one causes the other)

Page 23: Thinking Critically and Research Methods

EXPERIMENTAL METHODS

Because many factors influence everyday behaviors/attitudes, psychologists need to isolate and

control variables to establish cause and effect relationships. They do this using experiments.

Page 24: Thinking Critically and Research Methods

Experiments•A research method in which an investigator manipulates one or more factors (independent variables) to observe the effect on some behavior or mental process (the dependent variable). By random assignment of participants, the experimenter aims to control other relevant factors.•Manipulate the factors of influence•Hold other variables constant•Unlike correlational studies that uncover naturally occurring relationships, an experiment manipulates a factor to determine its effect.

Page 25: Thinking Critically and Research Methods

Variables – anything that can vary•Independent variable

•The variable manipulated by the experimenter

•Dependent variable•The outcome being studied as a result of the ind. variable

•Ex: Hypothesis – Pill X can reduce the symptoms of schizophrenia.• Ind. - Drug•Dep. – symptoms of schizophrenia

•Mnemonic (memory aid): make a if-then statement “IF the independent variable THEN the dependent variable.”

Page 26: Thinking Critically and Research Methods

Operational Definition•Specific definition of the independent and dependent variables•Very specific especially when variables are vague

•Ex: Hypothesis – Pill X can reduce the symptoms of schizophrenia.•Ind – Drug

•Operationalize: Pill X, placebo•Dep – symptoms of schizophrenia

•Operationalize: the amount of dopamine activity in the brain, the prevalence of disorganized speech

Page 27: Thinking Critically and Research Methods

Research groups•Experimental group

•Participants that receive the independent variable

•Control group•Participants NOT exposed to the independent variable

•Serves as a comparison for evaluating the effect of the ind. variable (sets a base-line)

•Ex: Hypothesis – Pill X can reduce symptoms of schizophrenia. Group A receives Pill X, while Group B receives a placebo (fake drug).•Exp. – Group A receiving Pill X (ind. variable)•Control – Group B receiving placebo

Page 28: Thinking Critically and Research Methods

Placebos•Placebo – a substance or treatment that has no effect apart from a person’s belief in it.

•Placebo effect – a person receiving the placebo may report to positive effects due to a belief in the drug/treatment

•Single blind study – participants do not know if they are in the experimental or control group

•Double blind study – participants nor researchers know who is in the experimental or control group•Reduces researcher bias - process where the scientists performing the research unconsciously influence the results, in order to portray a certain outcome.

Page 29: Thinking Critically and Research Methods

Experiments•Pros:

•Variables can be controlled and manipulated•Can determine cause-and-effect•Can be replicated

•Cons:•Labs can not always duplicate real-life environments•Can be expensive•Ethics can prohibit certain experiments

Page 30: Thinking Critically and Research Methods

COMPARING RESEARCH METHODSResearch Method

Basic Purpose How Conducted What is Manipulated

?

Weakness

Descriptive To observe and record behavior

Case studies, surveys, or naturalistic observations

Nothing No control of variables; single cases may be misleading

Correlational To detect naturally occurring relationships; to assess how well one variable predicts another

Compute statistical association, sometimes among survey responses

Nothing Does not specify cause and effect

Experimental To explore cause and effect

Manipulate one or more factors; random assignment to groups

Independent variable(s)

Sometimes not feasible; results may not generalize to other contexts; not ethical to manipulate certain variablesCrash Course – Research Metho

ds

Page 31: Thinking Critically and Research Methods

STATISTICAL REASONING

Page 32: Thinking Critically and Research Methods

Isn’t this AP Psych, not AP Stats?•After gathering dating with research methods, it needs to be organized and summarized using statistics so we can make inferences about the data.

•We make sense out of data using statistics.

Page 33: Thinking Critically and Research Methods

Measures of Central Tendency •a single score that represents a whole set of scores/data•Mean – the average of the scores/values•Median – the middle score /value in a distribution•Mode – the most frequent score/value

•Eg: Test scores – 60, 70, 70, 80, 80, 80, 80, 80, 90, 90, 100•Mean: 80•Mode: 80•Median: 80

Page 34: Thinking Critically and Research Methods

Measures in Variation•Allows us to see the variation or difference in a set of scores/values.•Range - the difference between the highest and lowest scores/values.

•Standard deviation – a measure of how much scores/values vary around the mean.

σ = Sum of (deviations from the mean)2

Number of scores

Page 35: Thinking Critically and Research Methods

Range and Standard Deviation •Eg: Test scores- 60, 70, 70, 80, 80, 80, 80, 80, 90, 90, 100•Mean: 80•Mode: 80•Median: 80

•Range: 100-60 = 40•The measure of dispersion of data

•Standard Deviation: 11•The degree to which scores differ from each other and vary around the mean value for the set (will always fall between 0 and ½ of range)• As the standard deviation approaches 0, the closer the scores are to each

other.• As the standard deviation approaches ½ of range, the more dispersed the

score are.

Page 36: Thinking Critically and Research Methods

55 60 65 70 75 80 85 90 95 100 1050

1

2

3

4

5

6Distribution of Quiz Scores

Quiz Scores

Freq

uenc

y

Mean, Median, Mode

Standard Deviation = 11 points (how much scores vary from each and around the mean)

Page 37: Thinking Critically and Research Methods

Normal Distributions•In a typical distribution of data:

•68% of scores will be within 1 standard deviation above or below the mean

•95% of scores are within 2 standard deviations above or below the mean.

•99.7% of scores are within 3 standard deviations above or below the mean.

Page 38: Thinking Critically and Research Methods
Page 39: Thinking Critically and Research Methods

55 60 65 70 75 80 85 90 95 100 1050

1

2

3

4

5

6Distribution of Quiz Scores

Quiz Scores

Freq

uenc

y

Mean, Median, Mode

-1 to +1 St.Dev. = 77%

-2 to +2 St.Dev. = 100%

Not a perfect distribution, therefore the quiz is not standardized .

Page 40: Thinking Critically and Research Methods

Statistical Significance•a statistical statement of how likely it is that an obtained result occurred by chance.•Uses a fancy formula that we do not need to know… HOWEVER…When a researcher

says…It means…

“When the results from the experimental group and the control group were compared, they were found to be statistically significant.”

The results could not have statistically occurred by chance…. There is a direct relationship between the variables.

“When the results from the experimental group and the control group were compared, they were NOT found to be statistically significant.”

There is not enough statistical evidence to say that the variables are in fact directly related and the results could have just occurred by chance.