Research Methods

AP Psych – Chapter 2Psychology’s Scientific Method

Alice F. Short Hilliard Davidson High School

Psychology Majors

• 2 Most Commonly Required Classes:– Research– Statistics

A SHORT Time to PonderWhy would these be the two most required

classes for psychology majors across the country?

Chapter Preview

• Psychology’s Scientific Method• Types of Psychological Research• Research Samples and Settings• Analyzing and Interpreting Data• Conducting Ethical Research• Thinking Critically About Research• Scientific Method and Health and Wellness

A SHORT Time to Ponder

• As a society, do we value critical thinking?• Is critical thinking uncomfortable sometimes?

Scientific Method• Science is a method.• (It’s a VERB)

• It’s not what you study, but how you study it.– any objective person can use the scientific method

1. observe some phenomenon2. formulate hypothesis and predictions3. test through empirical research4. draw conclusions5. evaluate the theory

Scientific Method – 1. Observe

• Step 1: Observe some phenomenon– curiosity– variables– theory

Scientific Method – 2. Hypothesize

• Step 2: Formulate hypotheses and predictions– testable prediction– derived from theory

Scientific Method – 3. Research

• Step 3: Test through empirical research– operational definition of variables– analyze data using statistical procedures

Scientific Method – 4. Conclusions

• Step 4: Draw conclusions– replication of results → reliability– If other people cannot replicate your study, then

your result are unreliable.– What could this potentially mean for your study?

(Think critically!)

Scientific Method – 5. Evaluate

• Step 5: Evaluate the theory– change the theory?– peer review and publication

• publish or perish– meta-analysis – method by which researchers combine

results across studies to establish the strength of an effect

– theory = broad umbrella category which can either be supported or refuted by testable hypotheses

Descriptive Research

• Goal: Describing a phenomenon– observation– surveys and interviews– case studies

• Descriptive research does not answer questions about how and why things are the

way they are

Correlational Research

• Goal: Identify relationships (does not mean there is a causal relationships)– correlation coefficient: r• -1.00 ≤ r ≤ 1.00

– strength of relationship: magnitude– direction of relationship: + / -

Correlational Coefficients

Scatter Plots

Correlational Research

• Positive Correlations– factors vary in same direction– ↑ and ↑ … or … ↓ and ↓

• Negative Correlations– factors vary in opposite direction– ↑ and ↓ … or … ↑ and ↓

Correlation and Causation

• correlation does not equal causation• third variable problem– Why would some people not WANT to consider a

third variable problem?• longitudinal design

Experimental Research

• Goal: Determine causation – random assignment – extremely important in

experimental design– independent variable(s) – manipulation– dependent variable(s) – measurement

• All of these vocabulary terms are very important to KNOW!

Experimental Research

• Experimental Group– independent variable is manipulated

• Control Group– treated equally, except no manipulation of

independent variable

Validity

• External Validity– representative of real world issues?– do results generalize to the real world?

• Internal Validity– are dependent variable changes the result of

independent variable manipulation?– bias? logical errors?

Bias and Expectations

• experimenter bias• demand characteristics• research participant bias• placebo effect• double-blind experiment

Example of Experimental Research:Self Esteem

• Baumeister’s research findings:– “high self esteem leads to aggression”

• Donnellan & Trzesniewski’s research findings: – “low self esteem leads to aggression”

• What accounts for these different findings?– lab-only aggression? – type of self esteem?

Applying Different Research Methods to the Same Phenomenon

• Example: Election of President Barack Obama

• Possible Research Methods:– observation– survey and interview– case studies– correlational research– experimental research

Research Sample

• Population – entire group about whom conclusion drawn

• Sample– portion of population actually observed

• Representative Sample– characteristics similar to population– opposite of “biased sample”

• Random Sample– equal chance of being selected

Research Settings

• “Artificial” world – laboratory setting– controlled setting

• Real world - natural setting– naturalistic observation

• DISCUSSION: What are the advantages and disadvantages of each setting?

Analyzing and Interpreting

Data

• Statistics– mathematical methods used to report

data• Descriptive Statistics

– describe and summarize data– Measures of Central Tendency

• mean• median• mode

– Measures of Dispersion• range• standard deviation

• Inferential Statistics– draw conclusions about data– does data confirm the hypothesis?– statistical significance– α = 0.05 (confidence level)– bridge between sample and

population

A SHORT Time to Ponder

• What is the difference between descriptive statistics and inferential statistics?

Research Ethics

• research participants have rights• Institutional Review Board (IRB)• APA Guidelines– informed consent– confidentiality– debriefing– deception

Animal Research in Psychology

• animal research has benefited humans• used by 5% of researchers• rats and mice used 90% of time• standards of care in animal research– housing– feeding– psychological and physical well being

Reality TV – Ethical Issues?

• informed consent?• Deception?• psychological and/or physical risk?• is the behavior real?

• DISCUSSION: What do YOU think?

A Wise Consumer…is skeptical yet open-minded!

• Cautions– exercise caution in applying group trends to

individual experience– avoid overgeneralizing results– look for converging evidence– question causal inferences– consider the source

Expressive Writing and Health

• Results of study on suicide v. accidental death– different survivor health – different survivor rate of talking about the loss

• Results lead to study on writing – those assigned to write about a trauma

experienced better physical health

Chapter Summary

• Explain what makes psychology a science.• Discuss common research settings and the main

types of research that are used in psychology.• Distinguish between descriptive statistics and

inferential statistics.• Discuss some challenges that involve ethics, bias,

and information.• Discuss scientific studies on the effect of writing

about ones trauma.

Chapter Summary

• Steps of the Scientific Method1. observe 2. hypothesize3. research4. conclude5. evaluate

• Research Methods and Settings– descriptive, correlational, and experimental studies

conducted in natural settings or the lab

Chapter Summary

• Data Analysis and Interpretation– descriptive and inferential statistics

• Challenges: Research Ethics and Bias– APA guidelines and the IRB

• Expressive Writing and Health and Wellness– benefits of writing about trauma