Research Methods in Psychology: Types of Psychology Studies

Main Ideas & Concepts (Research Methods in Psychology)

Purpose of Research in Psychology

• Psychologists use different techniques to collect data to draw conclusions about the mind and behavior.
• Well-designed research supports logical, evidence-based conclusions rather than relying on common sense or assumptions.
• Research methods help determine whether findings reflect relationships or, when possible, cause-and-effect.

Major Types of Psychology Studies (Key Details & Distinctions)

Experiments

• A researcher manipulates and controls variables to observe effects on other variables.
• Designed to assess cause-and-effect relationships.
• Conducted using the scientific method and can be done:
  • In a lab
  • In the field
• Quasi-experiments
  • Similar to experiments, but used when full experimental control/manipulation is not possible.
  • Can be conducted in lab and/or field settings.

Correlational Studies

• Examine relationships between two or more variables.
• Used when experiments are not possible or ethical.
  • Example: studying alcohol use and anger (you would not repeatedly administer alcohol to induce anger).
• Limitation: correlation cannot prove cause-and-effect.
  • Example: self-esteem vs. career promotions—promotions may not be the sole cause; other factors could contribute.

Case Studies

• Focus on one person, group, or specific situation.
• Example source: Sigmund Freud, who used case studies to build theories.
• Famous historical examples:
  • Phineas Gage
    • Injury: an iron rod shot through his frontal lobe, causing permanent brain damage.
    • Outcome: he survived; doctors recorded changes in behavior and demeanor and linked them to brain location.
    • Lesson: supported the idea that personality and frontal lobe function are related (with later confirmation work).
  • Genie
    • A girl who experienced severe child abuse and neglect and was raised in isolation.
    • She was attached to a potty chair, fed only baby food, and spoke very little/could not talk when escape occurred.
    • After escaping at age 13, a team helped her learn speech, walking, and socialization.
    • Lesson: contributed to understanding linguistic development and development timelines/stages.

Survey Research

• Researchers create a survey/test/questionnaire about a topic or variable.
• Administer it to a random sample of participants.
• Strengths:
  • Effective and fast for gathering information.
• Limitations:
  • Depends on:
    • Quality of the questions
    • Whether participants accurately represent the intended population.

Longitudinal Studies

• A type of correlational research conducted over weeks, months, years, or decades.
• Example:
  • Track participants’ diets starting in their 30s and follow them for life to determine whether dietary changes slow dementia symptoms and when symptoms begin.
• Strengths:
  • Valuable for studying development and lifespan issues.
• Limitations:
  • Expensive
  • Other variables can affect results
  • Risk of participant drop-out

Cross-sectional Studies

• Compare participants of different ages at one point in time.
• Example:
  • Compare intelligence scores across age groups to infer how scores may change across the lifespan.
• Strengths:
  • Good for describing the current population
  • Can show characteristics of a population at a time
• Limitation:
  • Does not manipulate variables → cannot determine cause-and-effect.

Naturalistic Observation

• Observing behavior in people’s real-life environments (“in the field”).
• Used when lab research is too expensive or would alter participant behavior.
• Example:
  • To study the student-teacher relationship, researchers observe time in actual classrooms rather than recreating one in a lab.

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Methodology / Instructional Content Included

When Conducting Experiments (General Approach)

• Manipulate and control variables to see effects on other variables.
• Follow the scientific method.
• Decide whether to run the study in a lab or in the field.

When Choosing Research Methods (Implicit Decision Rules)

• Use correlational studies when experiments are not possible or ethical.
• Use surveys to gather information from large groups efficiently.
• Use longitudinal studies to track changes over long periods (development/lifespan).
• Use cross-sectional studies to compare different age groups at one time.
• Use naturalistic observation when lab settings are impractical or would distort behavior.
• Use case studies when focusing deeply on a single person/group/situation to generate insights.

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Speakers / Sources Featured

• Freud (named as Sigmund Freud)
• Phineas Gage
• Genie