Module 4–6: The Scientific Method, Conducting Psychological Research, and Ethics — Comprehensive Study Notes

The Scientific Method and Psychological Research

• Definition of the scientific method: a systematic approach through which psychologists acquire knowledge and understanding about behavior and other phenomena of interest.

• Role of theories in research:

  • Broad explanations and predictions concerning phenomena of interest.

  • Provide a framework for understanding relationships among a set of unorganized facts or principles.

• Role of hypotheses in research:

  • Hypotheses are testable predictions stemming from theories, not questions.

  • They translate a theory into specific, testable predictions.

  • Example hypothesis: The more people who witness an emergency situation, the less likely it is that help will be given to a victim.

• Operational definitions and variables:

  • Operational definition: translation of a hypothesis into specific, testable procedures that can be measured and observed.

  • Variables: Behaviors, events, or other characteristics that can change or vary in some way.

• Theoretical testing as a driver of scientific progress:

  • Using formal theories and hypotheses helps place observations in a coherent framework.

  • They guide deductions about unexplained phenomena.

  • They generate ideas for future investigation.

Bystander Effect and Diffusion of Responsibility

• Theory example: diffusion of responsibility (bystander effect).

  • Proposed by Bibb Latane and John Darley to understand why bystanders fail to intervene in emergencies ( Kitty Genovese case).

  • Core idea: as the number of bystanders increases, the perceived share of responsibility for helping decreases for each individual.

• Classroom prompt ideas:

  • How could you test diffusion of responsibility in a real-life scenario?

Hypotheses: Crafting Testable Predictions

• Key features:

  • Hypothesis is a testable statement, not a question.

  • It is derived from a theory and is framed in a way that can be empirically tested.

• Example: The more people who witness an emergency, the less likely it is that help will be given.

• Operational definitions and variables:

  • Operational definitions convert abstract concepts into measurable procedures.

  • Variables are the aspects of the study that can vary (eg, number of witnesses, likelihood of helping).

Module 5: Conducting Psychological Research

• What is research?

  • Systematic inquiry aimed at discovering new knowledge.

  • Key to evaluating the accuracy of hypotheses and theories.

• Descriptive research: systematic investigation of a person, group, or pattern of behavior

  • Several types exist (archival, naturalistic, survey, case study, etc.)

Important Terms for Research Designs

• Sample: a selected segment of the population used to represent the group being studied.

• Representative sample: a segment that closely parallels the larger population on relevant characteristics.

• Random selection: each group member has an equal chance of being included.

Archival Research

• Existing data are examined to test a hypothesis (eg, census documents, college records, online databases, newspaper clippings).

• Advantage: inexpensive.

• Disadvantage: data may not be in a form that fully tests the hypothesis.

Naturalistic Observation

• Investigator observes naturally occurring behavior without changing the situation.

• Advantage: sample reflects real-world behavior in natural habitat.

• Disadvantage: limited ability to control factors of interest.

Survey Research

• People are asked a series of questions about behavior, thoughts, or attitudes.

• Advantage: can infer how a larger group would respond if the sample is representative.

• Disadvantages: results depend on representativeness; respondents may be unwilling to disclose socially undesirable attitudes.

The Case Study

• In-depth, intensive investigation of an individual or small group.

• Usually involves unique situations not easily studied experimentally.

• Often include psychological testing.

• Advantage: can yield rich insights into unique situations.

• Disadvantage: limited generalizability to broader populations.

Correlational Research

• Purpose: examine the relationship between two sets of variables to determine if they are associated or correlated.

• Variables: behaviors, events, or other characteristics that can vary.

• Correlation coefficient (r): represents the strength and direction of the relationship between two variables.

  • Range: $r ext{ ranges from } +1.00 ext{ to } -1.00$

  • Positive relationship: as one variable increases, the other tends to increase.

  • Negative relationship: as one variable increases, the other tends to decrease.

  • No relationship: r close to 0.

• Major limitation: correlational designs cannot demonstrate causality.

• Example: Figure illustrating aggression and TV viewing shows potential confounding variables that can influence observed relationships.

• Caution: correlation does not imply causation; other variables may account for observed associations.

Experimental Research

• Definition: investigation of the relationship between two or more variables by producing a change in one variable and observing the effects on another.

• Experimental manipulation: deliberate change introduced by the experimenter.

• Experimental groups and control groups:

  • Experimental group: receives the treatment or manipulation.

  • Control group: receives no treatment or a baseline condition.

• Key variables:

  • Independent variable (IV): the variable manipulated by the experimenter.

  • Dependent variable (DV): the variable measured; expected to change as a result of IV changes.

• Random assignment to condition:

  • Participants are assigned to different groups by chance.

  • Aims to create equivalent groups and reduce bias.

• Significant outcome:

  • Statistically meaningful results; the differences between groups are large enough to be unlikely due to chance.

  • Replicated research: repeating the study in different settings and with different participants to increase confidence in findings.

• True experiment example:

  • Kaplan and Manuck (1989) illustrated true experimental designs (as referenced in the text).

• Latané and Darley diffusion of responsibility study:

  • Classic finding: as group size increases, helping behavior decreases.

  • Visual and textual references: Latané and Darley, diffusion of responsibility, Journal of Personality and Social Psychology, 1968, 8, 377–383.

• Were Latané and Darley right?

  • The question centers on whether differences observed are statistically meaningful.

  • A significant outcome provides evidence that the findings are not due to random variation.

Research Strategies: Summary Table (Descriptive, Correlational, and Experimental)

• Descriptive and correlational research

  • Description: researcher observes a preexisting situation without changing it.

  • Advantage: provides insight into relationships between variables.

  • Shortcoming: cannot determine causality.

• Archival research

  • Description: examines existing data to test hypotheses.

  • Advantage: data are readily available; easy data collection.

  • Shortcoming: data availability and relevance can limit testing.

• Naturalistic observation

  • Description: observe behavior in natural environment without manipulation.

  • Advantage: high ecological validity.

  • Shortcoming: less control over conditions; potential observer effects.

• Survey research

  • Description: representative sample asked questions.

  • Advantage: can infer attitudes and behaviors of a larger population.

  • Shortcomings: sampling bias; social desirability and honesty concerns.

• Case study

  • Description: intensive study of an individual or small group.

  • Advantage: rich, detailed information; can illuminate unique cases.

  • Shortcoming: limited generalizability.

• Experimental research

  • Description: manipulate an IV to observe effects on a DV; includes random assignment and control conditions.

  • Advantage: can determine cause-and-effect relationships.

  • Shortcomings: requires careful control; ethical and practical constraints.

  • Validity requirements: random assignment, well-conceptualized IV and DV, and other controls.

Moving Beyond the Study

• Replicated research: repetition of studies to increase confidence in prior findings; may use different procedures, settings, and participants.

• Meta-analysis: combines results of many studies into one overall conclusion; helps resolve conflicting findings and assess overall effect sizes.

• Replication crisis: many replication attempts fail to reproduce original findings in recent years; ongoing concern in psychology.

Module 6: Critical Research Issues and Ethics

• Ethical guidelines overview:

  • Psychological research in the United States follows APA ethical guidelines.

  • There are five key provisions regulating research with human participants in the most recent guidelines.

The Ethics of Research (Human Participants)

• Core provisions:

  • Protection of participants from physical and mental harm.

  • Right to privacy regarding behavior.

  • Participation must be voluntary.

  • Informed consent: participants are told the basics of the study before participating.

  • Independent review: experiments must be reviewed by an independent panel before conduct (eg, institutional review boards).

• Informed consent and debriefing:

  • Informed consent: signed document stating awareness of procedures.

  • Debriefing: explanation of the study and procedures after participation.

Animals in Psychological Research

• APA (2011) stance: animals may be used under certain conditions if the research meets criteria.

  • Acceptable scientific purpose.

  • Reasonable expectation that the research will increase knowledge about behavior, increase understanding of the species, or benefit health or welfare of humans or other animals.

  • Minimization of discomfort, illness, and pain; use of distressing procedures only when no alternatives exist and when the research has prospective value.

• Justification and alternatives:

  • If possible, use nonhuman subjects or noninvasive methods to achieve goals.

  • If animal research is used, it should maximize benefits and minimize suffering.

Threats to Experimental Validity: Diversity in Research Subjects

• WEIRD problem: most research uses participants from Western, Educated, Industrialized, Rich, Democratic societies.

• Implications: findings may not generalize to other populations or cultures.

Threats to Experimental Validity: Avoiding Experimental Bias

• Experimental bias: factors that distort the effect of the IV on the DV.

  • Experimenter expectations can unintentionally cue participants to behave in a certain way.

  • Participant expectations about the research can influence outcomes.

• Class prompts:

  • In the bystander scenario, possible cues by researchers that could influence results.

  • Participant expectations that could affect results.

• Placebo and double-blind procedures:

  • Placebo: a false treatment with no significant effect.

  • Double-blind: neither the experimenter nor the participant knows the nature of the treatment.

Notes:

• Throughout these notes, remember that descriptive and correlational studies reveal associations but do not prove causation. Experimental designs that involve random assignment and manipulation of an IV can establish causal relationships, provided that confounding variables are controlled.

• Real-world application examples include the diffusion of responsibility in emergencies and the interpretation of replication and meta-analysis in assessing the robustness of findings.

• Ethical considerations are central to all research involving humans and animals, with strict guidelines to minimize harm and maximize knowledge and welfare.

The Scientific Method and Psychological Research

• Scientific Method: Systematic approach to psychological knowledge.

• Theories: Broad explanations providing a framework for understanding phenomena.

• Hypotheses: Testable predictions derived from theories; e.g., more witnesses in an emergency = less help.

• Operational definitions: Translate hypotheses into specific, measurable procedures.

• Variables: Characteristics that can change or vary.

• Theoretical testing drives scientific progress by providing frameworks and guiding future investigation.

Bystander Effect and Diffusion of Responsibility

• Theory example: diffusion of responsibility (bystander effect) by Latane and Darley.

• Core idea: Increased bystanders lead to decreased individual responsibility to help.

Hypotheses: Crafting Testable Predictions

• Key features: Testable statements derived from theories, not questions.

• Example: More witnesses = less help.

• Operational definitions: Convert concepts into measurable procedures.

• Variables: Aspects of the study that can vary (e.g., number of witnesses, helping likelihood).

Module 5: Conducting Psychological Research

• Research: Systematic inquiry to discover new knowledge, testing hypotheses and theories.

• Descriptive research: Investigates behavior patterns; types include archival, naturalistic, survey, case study.

Important Terms for Research Designs

• Sample: Subset of population studied.

• Representative sample: Parallels the larger population.

• Random selection: Equal chance for each member to be included.

Descriptive Research Types

• Archival Research: Examines existing data.

  • Advantage: Inexpensive.

  • Disadvantage: Data may not fit hypothesis.

• Naturalistic Observation: Observes behavior in natural settings.

  • Advantage: Real-world behavior.

  • Disadvantage: Limited control.

• Survey Research: Asks series of questions.

  • Advantage: Can infer attitudes of larger groups (if sample is representative).

  • Disadvantage: Sampling bias, social desirability.

• Case Study: In-depth investigation of individual/small group.

  • Advantage: Rich insights into unique situations.

  • Disadvantage: Limited generalizability.

Correlational Research

• Purpose: Examines relationships between variables (association, not causation).

• Correlation coefficient ($r$): Measures strength and direction ($-1.00$ to $+1.00$).

  • Positive: Both variables increase/decrease together.

  • Negative: One increases, other decreases.

  • No relationship: $r$ near $0$.

• Major limitation: Cannot prove causation; confounding variables are possible.

Experimental Research

• Definition: Investigates cause-and-effect by manipulating an independent variable (IV) and observing its effect on a dependent variable (DV).

• Groups:

  • Experimental group: Receives treatment.

  • Control group: Baseline/no treatment.

• Random assignment: Participants assigned by chance to create equivalent groups, reducing bias.

• Significant outcome: Statistically meaningful results, unlikely due to chance.

• Replicated research: Repeating studies for increased confidence.

• Example: Latané and Darley's diffusion of responsibility study showed increased group size decreases helping.

Research Strategies: Summary

• Descriptive/Correlational:

  • Description: Observes preexisting situations.

  • Advantage: Insights into relationships.

  • Shortcoming: No causality.

• Archival: Examines existing data; Inexpensive but data limitations.

• Naturalistic Observation: Observes natural behavior; High ecological validity but less control.

• Survey Research: Questions representative sample; Infers attitudes but prone to bias.

• Case Study: In-depth individual/group study; Rich detail but limited generalizability.

• Experimental Research: Manipulates IV to observe DV; Determines cause-and-effect but