unit 2: research methods: thinking critically with psychological science

Unit 2: Research Methods: Thinking Critically with Psychological Science

WHY IS RESEARCH SO IMPORTANT?

Unit 2: Research Methods

Hindsight Bias Tendency to believe,

after learning an outcome, that one would have foreseen it.“I knew it all along”“Hindsight is 20/20”

OverconfidenceThink we know

more than we do!Together with

hindsight bias, can lead to overestimate our intuition

The Scientific Attitude Three main components

Curious eagernessSkeptically scrutinize competing ideasOpen-minded humility before nature

Critical Thinking Critical Thinking: Thinking that does not

blindly accept arguments & conclusions. “Smart thinking”Four elements:

Examines assumptionsDiscerns hidden valuesEvaluates evidenceAssesses conclusions

WHY IS RESEARCH SO IMPORTANT?

Unit 2: Research Methods

The Scientific Theory Theory = A mere “hunch” Scientific theory = Observations Scientific theory = explains through an

integrated set of principles that organizes observations and predicts behaviors or events.

The Scientific Method Evaluates competing ideas with careful

observations & rigorous analysis to describe and explain human nature.

Observations Problem Hypothesis Experiment Data Conclusion Replication

Observations Information about the problem.

Problem Question based upon

observations.

Hypothesis A statement of relationship

between or among variable. A suggested solution to the

problem.

If…Then…

Experiment

A procedure to test the hypothesis.

Control – experiment without the variable

Variable – factor being tested

Data

Results of the experiment.

Conclusion

The answer to the hypothesis.

Replicate In order to verify the results,

experiments must be retested.Operational definitions

The Scientific Method

A good theory is useful if it:Effectively organizes a range of

self-reports and observationsImplies clear predictions that

anyone can use to check the theory

The Scientific Method1) Identify a Problem2) State Observations about the problem3) Form a Hypothesis about the problem (if…

then…)4) Design an Experiment to test the

hypothesis5) Collect Data6) Form a Conclusion7) Replicate

Experimental Projects @ WHS Observations Problem Hypothesis Correlational study?

Positive or Negative? Specific Experiment

All steps included Operational

definitions Data Collected Conclusion Replicate

What is your population? How did you find

sample? Control Group Experimental Group Independent Variable Dependent Variable Confounding Variables Blind/Double Blind? Placebo Any Bias?

OBSERVATION AND BIAS

Module 2: Research Strategies

Observation

Gathering of information by simply watching subjects

Can lead to bias

Bias

A factor unfairly increases a researcher reaching a particular conclusion

Researcher Bias

Notice evidence which supports one point of view or hypothesis.

Objectivity tends to reduce bias.

Participant Bias

Subjects respond in ways they believe the researcher wants them to behave

Know they are being observed Naturalistic Observation

Naturalistic Observation

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

Unaware they are being watched

CASE STUDIES

Module 2: Research Strategies

Case Study Observation technique in which one

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

Very open to bias… Why?

CORRELATION

Module 2: Research Strategies

Correlational Study Determines the degree

to which two variables are related to one another…

Correlation Coefficient: a statistical index of the relationship between two things (from -1 to +1).

Positive Correlation Value of 1 variable increases (or decreases)

so does the value of the other variable.

Negative Correlation Value of 1 variable increases, the value

of the other variable decreases.

Zero Correlation There is no relationship

whatsoever between the two variables.

Correlational Study

Don’t imply a cause and effect relationship Doesn’t determine why 2 variables are

related-- Helpful in making predictions.

SURVEYS

Module 2: Research Strategies

Survey Method Relies on self-reports: questionnaires,

interviews, and surveys. Efficient and inexpensive

Population The total group being studied from which

a sample is drawn.

Random Sample Represents a population fairly:

Equal chance of being included. If it is not random it is said to

be biased.

Experimental Projects @ WHS Observations Problem Hypothesis Correlational study?

Positive or Negative? Specific Experiment

All steps included Operational

definitions Data Collected Conclusion Replicate

What is your population? How did you find

sample? Control Group Experimental Group Independent Variable Dependent Variable Confounding Variables Blind/Double Blind? Placebo Any Bias?

EXPERIMENTS: INDEPENDENT

AND DEPENDENT VARIABLES

Module 2: Research Strategies

Independent Variable vs.

Causes something to happen

Manipulated by the experimenter

Should change the dependent variable

Effected by independent variable

Outcome of experiment

Variable being measured

Dependent Variable

Control Group

Not exposed to the independent variable Results are compared to those of the

experimental group

Blind procedure Participants are ignorant (blind) to the

expected outcome of the experiment Single blind procedure Double blind procedure?

Placebo Non-active substance or condition instead

of a drug or active agent Given to the control group

Placebo Effect Video Time… http://

player.discoveryeducation.com/index.cfm?guidAssetId=5F290E71-AB90-4842-A4D7-FB0DB55A682C&blnFromSearch=1&productcode=US

Experimental Projects @ WHS Observations Problem Hypothesis Correlational study?

Positive or Negative? Specific Experiment

All steps included Operational

definitions Data Collected Conclusion Replicate

What is your population? How did you find

sample? Control Group Experimental Group Independent Variable Dependent Variable Confounding Variables Blind/Double Blind? Placebo Any Bias?

LONGITUDINAL AND

CROSS-SECTIONAL STUDIES

Module 2: Research Strategies

Longitudinal Study

Study same group of individuals many years Very expensive and difficult to conduct

Cross-Sectional Study

Simultaneously study subjects from different age groups

Cheaper, easier Differences may be due

to factors other than development

Longitudinal/Cross Sectional Study

ETHICS:HUMAN RESEARCH

(4 BASIC PRINCIPLES)

Module 2: Research Strategies

1. Informed Consent General nature of the research Any potential risks Refuse participation or withdraw

2. Right to be Protected from Harm/Discomfort Conducted under certain circumstances Only with the informed consent

3. Right of Confidentiality

Individual data about participants should never be discussed or released.

4. Right to Debriefing Receive complete explanation of research

at end of the study. Important if research involves deception.

ETHICS:ANIMAL RESEARCH

Module 2: Research Strategies

Reasons for Animal Research Interest in animal

behavior Data may apply to

humans Easier due to the

shorter life span Easier to control Not ethical to

perform on humans

• http://videos.howstuffworks.com/hsw/23818-the-brain-and-spinal-cord-an-experiment-video.htm

Statistical Reasoning in Everyday Life

Describing DataMeasures of Central Tendency

Central Tendency = a single score that represents a whole set of scores.

Describing DataMeasures of Central Tendency

Mean = the average of a distribution, obtained by adding the scores and then dividing by the # of scores.

Describing DataMeasures of Central Tendency

Median = the middle score in a distribution, half the scores are above it and half are below it.

Describing DataMeasures of Central Tendency

Mode = the most frequently occurring score(s) in a distribution

Describing DataMeasures of Variability

Range = the difference between the highest and lowest score in a distribution.

Standard Deviation= a computed measure of how much scores vary around the mean score.

Describing DataMeasures of Variability

Normal Curve (bell shaped)

= a symmetrical, bell-shaped curve that describes the distribution of many types of data; most scored fall near the mean (68 percent fall within one standard deviation of it) and fewer and fewer near the extremes.

Making InferencesWhen Is an Observed Difference Reliable?

Representative samples are better than biased samples

Less-variable observations are more reliable than those that are more variable

More cases are better than fewer

Making InferencesWhen Is a Difference Significant?

Statistical significanceThe averages are reliableThe differences between averages

is relatively largeDoes imply the importance of the

results

THE END

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Research Methods

Play “Aliens Have Landed” (11:25) Segment #3 from Scientific American Frontiers: Video Collection for Introductory Psychology (2nd edition).

Follow with a discussion on the unbiased scientific research.

Scientific Method

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

Psychology is thereby considered a science. An application of critical thinking through

observation and statistical analysis

Research and Research Methodology

• Method of asking questions then drawing logical supported conclusions

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

Common Sense

• Conclusions based solely on personal experience and sensible logic

• Can lead to incorrect conclusions• The scientific method can help you

better evaluate your hunches

Common Sense

What are the Odds of Each?

What are the Odds of Each?

1 in 2,598,960

What are the Odds of Each?

1 in 2,598,960 1 in 2,598,960

How to Read a Correlation