Psychology Research Methods

Chapter 1: Research Producers and Research Consumers

• Research Producers: These are individuals who actively conduct research studies, performing the experiments and gathering data.

• Research Consumers: These are individuals who read research and apply that information to their professional or personal work.

• The Importance of the Producer Role:

  • It is essential for university-level coursework in psychology.

  • It prepares students for graduate school environments.

  • It is necessary for those working or intending to work in a research laboratory setting.

• The Importance of the Consumer Role:

  • Necessary for succeeding in psychology courses.

  • Required for evaluating printed or online news stories that are based on scientific research.

  • Critical for future careers that utilize evidence-based treatments (treatments supported by research evidence).

• Benefits of Being a Good Consumer:

  • By being critical of incoming information, a person can gain more accurate information.

• Scientists as Empiricists:

  • Theory: A tool used to describe general principles regarding how various variables relate to one another.

  • Hypothesis: A specific prediction derived from a theory.

  • Data: A set of observations collected by researchers.

  • Empiricism: The practice of collecting data to develop, support, or challenge a theory.

• The Theory-Data Cycle:

  • Scientific studies support or challenge theories, but they do not prove theories.

  • What Makes a Good Theory?

    • Falsifiability: There must be a specific condition under which the theory could be proven incorrect.

    • Parsimony: Given the choice between multiple solutions, the simplest solution is considered the best.

    • Weight of Evidence: Researchers should conduct studies that both support and do not support the hypothesis to see where the bulk of the evidence lies.

• Research Problem Classifications:

  • Basic Research: Research conducted with the goal of adding to general knowledge.

  • Translational Research: Serves as a bridge between basic and applied research, applying basic research to potential solutions.

  • Applied Research: Research performed specifically to solve a practical, real-world problem.

• The Dissemination of Scientific Work:

  • Peer-Review Journal Article: A document written by experts and reviewed by other professionals in the field before publication.

  • The Peer-Review Process: This process serves as the gatekeeper to judge the quality and validity of research.

  • Journalism: News and commentary intended for the general public, typically consumed via television, websites, or newspapers.

Chapter 2: Comparison Groups, Confounds, and Biases

• The Problem with Experience:

  • Experience has no comparison group. A comparison group allows a researcher to compare at least two conditions: one with the variable/treatment and one without it.

  • Experience is Confounded: A confound is a third variable that affects both the independent and dependent variables, potentially leading to incorrect conclusions. Researchers aim to isolate variables to prevent confounds.

• Research is Probabilistic:

  • Findings in behavioral research are not expected to explain every single case at all times. Results are based on probabilities rather than certainties.

• Biases in Intuition:

  • Being Persuaded by a Good Story: Accepting a claim just because it sounds logical or reasonable.

  • Availability Heuristic: Being persuaded by whatever information easily comes to mind.

  • Present/Present Bias: Failing to think about what we cannot see; focus is only on what is present.

  • Confirmation Bias: The tendency to focus exclusively on evidence that supports our existing beliefs or evidence we like best.

  • Bias Blind Spot: The belief that we are unlikely to fall prey to other biases or that they do not affect us; related to overconfidence.

• Consulting Scientific Sources:

  • Journal Articles: The most important source of information in psychology.

  • Empirical Journal Article: Reports on a single, original research study.

  • Review Article: Summarizes many different studies on a given topic.

  • Meta-Analysis: A statistical technique that combines results from many studies to determine the overall effect size.

• Components of an Empirical Article:

  • Abstract: A brief summary or "spoiler" of the research.

  • Introduction: Provides general background information and the rationale for the study.

  • Method: A detailed explanation of how the research was conducted.

  • Result: The outcome of the methods used, including statistical data.

  • Discussion: Includes implications of the study, strengths, limitations, and the researcher’s opinions.

  • Reference: A list of sources cited in the article.

• Journalism vs. Misinformation:

  • Disinformation: The deliberate creation and sharing of information that is known to be false.

  • Malinformation: True information that is shared with the intent to be hurtful.

Chapter 3: Three Claims and Four Big Validities

• Defining Variables:

  • Variable: An element that changes or varies; it must have at least two levels or values.

  • Constant: An element that does not vary within a study.

  • Measured Variable: Observed and recorded by the researcher (e.g., height, weight, hair color).

  • Manipulated Variable: A variable that the researcher assigns participants to, controlling the levels.

• Conceptual vs. Operational:

  • Conceptual Variable: Theoretical concepts that exist in the mind (e.g., depression, anxiety). The definition is similar to a dictionary definition.

  • Operational Variable: The specific thing that can be measured or manipulated in a study.

  • Operational Definition: Defining a concept by the specific way it will be measured in an experiment.

• Three Claims in Research:

  • Frequency Claims: Describe a particular level or degree of a single variable. This involves only one measured variable.

  • Association Claims: Argue that there is a relationship between two variables where as one changes, the other tends to change as well (covary). This involves two measured variables and uses correlation.

  • Causal Claims: Argue that one variable causes changes in the level of another variable. Requires at least one measured and at least one manipulated variable.

• The Four Big Validities:

  • Validity: The appropriateness, reasonableness, and accuracy of a conclusion.

  • Construct Validity: Measures how well the variables in a study are measured or manipulated. It looks at the operationalization and conceptual definition.

  • Statistical Validity: Evaluates how well the statistics were performed. It checks for correct analysis and the minimization of Type 1 (false positive) and Type 2 (false negative) errors.

  • Internal Validity: The ability to rule out confounds by keeping everything constant and isolating variables to ensure results are not due to outside factors.

  • External Validity: The degree to which results are generalizable outside of the lab to more realistic settings.

• Three Criteria for Causal Claims:

  • Covariance: The variables must change together.

  • Temporal Precedence: The cause must happen before the effect (the "if" must precede the "then").

  • Internal Validity: Ensuring no third variable (confound) is responsible for the relationship.

• Supporting Causal Claims:

  • Experiment: The method used to support causal claims where one variable is manipulated and the other is measured.

  • Independent Variable (IV): The manipulated variable; represents the cause or input.

  • Dependent Variable (DV): The measured variable; represents the effect or output.

  • Random Assignment: A procedure ensuring every participant has an equal chance of being in any group, strengthening internal validity.

Chapter 4: Ethics in Research

• The Belmont Report Core Principles:

  • Principle of Respect for Persons: Includes informed consent, informing participants of risks and benefits. Recognizes that certain groups (e.g., children, prisoners) have less autonomy and require special protection.

  • Principle of Beneficence: Focuses on "doing good." Researchers must assess potential harm to participants against potential benefits to society.

  • Principle of Justice: Focuses on the balance between who participates in the research and who benefits from it. It asks who bears the burden of participation.

• Ethical Standards for Research:

  • Institutional Review Board (IRB): A committee responsible for ensuring human research is conducted ethically.

  • Informed Consent: An explanation of the study provided in written format before a person agrees to take part.

  • Deception:

    • Omission: Withholding specific details of a study.

    • Commission: Lying to participants about the study.

  • Debriefing: The process where the researcher explains the true nature of the experiment to the participant after it is finished.

• Research Misconduct:

  • Data Fabrication: Researchers invent data that does not exist.

  • Data Falsification: Researchers delete or influence data to make participants seem to act in a certain way.

  • Plagiarism: Representing the words or ideas of others as one's own.

• Animal Research Ethics (The 3 Rs):

  • Replacement: Finding alternatives to using animals when possible.

  • Refinement: Modifying procedures to reduce animal distress.

  • Reduction: Using the fewest number of animals possible.

Chapter 5: Measurement, Reliability, and Validity

• Three Common Types of Measures:

  • Self-Report Measure: Participants answer questions about themselves in a questionnaire or interview.

  • Observational Measure: Tracking and recording observable behaviors.

  • Physiological Measure: Collecting biological data such as brain activity, heart rate, or cortisol levels.

• Scales of Measurement:

  • Categorical Variables: Variables that fall into discrete categories.

  • Quantitative Variables: Coded with meaningful numbers.

    • Ordinal: Based on order or ranking (e.g., small, medium, large).

    • Interval: Precise increments between levels (no true zero).

    • Ratio: Precise increments with a true zero point.

• Three Types of Reliability (Consistency):

  • Test-retest Reliability: Consistent scores are produced every time the measure is used on the same group.

  • Interrater Reliability: Consistent scores are obtained regardless of who is performing the measurement.

  • Internal Reliability: Participants provide consistent patterns of responses regardless of the phrasing of specific questions within a single measure.

• Evaluating Reliability using Correlation Coefficient $r$:

  • Test-retest Evaluation: Rank participants twice and compute $r$. If $r > 0.5$ and is positive, reliability is good. If $r < 0.5$, reliability is low.

  • Interrater Evaluation: Two observers rate the same group. If $r \ge 0.7$ and is positive, reliability is good. Weak positive $r$ indicates poor reliability. Negative $r$ is considered terrible.

  • Internal Evaluation: Uses Cronbach’s Alpha to see if items correlate strongly. If they do, they can be averaged for a single score.

• Validity (Accuracy):

  • Face Validity: A subjective assessment of whether the measure looks like what it is intended to measure.

  • Content Validity: A subjective assessment that the measure contains all theoretical components of the construct.

  • Criterion Validity: Checks if the measure is related to a concrete outcome.

    • Concurrent Validity: Correlation with a current outcome (e.g., cortisol levels and current stress behavior).

    • Predictive Validity: Correlation with a future outcome.

    • Known Groups Paradigm: Examining if the measure can distinguish between groups whose behavior is already understood.

  • Convergent Validity: A measure should correlate strongly with other measures intended to capture the same construct (similarity).

  • Discriminant (Divergent) Validity: A measure should correlate less strongly with measures of different or unrelated constructs (difference).