Research Methods in Psychology

The Experimental Method

• Aim: A statement outlining the researcher's goal for a research study.
• Hypothesis: A testable statement about the relationship between variables.
• Standardized Procedures: Consistent steps for all participants to ensure replication.
• Independent Variable (IV): The variable directly manipulated by the researcher.
• Dependent Variable (DV): The variable measured for changes based on the IV.
• Extraneous Variables: Variables that may influence the DV but are not the IV.

Hypothesis, Piloting, and Confederates

• Directional Hypothesis: Predicts a specific direction of difference between two conditions, also known as a one-tailed hypothesis.
• Non-Directional Hypothesis: Predicts a difference between two conditions without specifying direction, also known as a two-tailed hypothesis.
• Pilot Study: A small-scale trial to test the design and identify potential issues before the main study.
• Confederate: An individual instructed by the researcher to behave in a specific way during the study.

Controlling Variables

• Confounding Variable: A variable that systematically varies with the IV, potentially affecting the DV.
• External Validity: The extent to which findings can be generalized to other settings, populations, and times.
• Internal Validity: The degree to which an observed effect is due to the experimental manipulation, not confounding variables.
• Mundane Realism: The extent to which a study mirrors real-life situations.

Experimental Designs

• Repeated Measures: All participants complete all conditions, minimizing participant need but introducing order effects (fatigue, practice).
• Independent Groups: Participants are randomly assigned to groups and tested on one IV, eliminating order effects but requiring more participants with less control over extraneous variables.
• Matched Pairs: Two participants are matched based on key characteristics and placed in different groups, eliminating order effects but being time-consuming.

Types of Experiments

• Laboratory Experiment: Conducted in a controlled setting, minimizing extraneous variables and allowing for replication but lacking ecological validity.
• Field Experiment: Conducted in a natural setting, promoting ecological validity but prone to confounding variables and ethical concerns due to covert observation.
• Natural Experiment: An experiment where the IV is not directly manipulated, offering high ecological validity but unable to establish causality.
• Quasi-Experiment: Focuses on a naturally occurring IV, allowing comparisons between different groups but lacking internal validity and control over group allocation.

Experimental Issues

• Demand Characteristics: Cues that make participants aware of the study's aims, influencing their behavior.
• Investigator Effects: Actions by the researcher that influence participants' performance beyond the intended manipulation.
• Single-Blind Design: Participants are unaware of the study's aims.
• Double-Blind Design: Both participants and researchers are unaware of the study's aims.
• Experimental Realism: An engaging and immersive task that reduces participants' awareness of being observed.

Sampling Methods

• Population: The entire group of interest in a research study.
• Sample: A smaller group drawn from the population, intended to represent the whole.
• Generalization: Applying findings from a sample to the broader population.
• Bias: A systematic distortion in the findings.
• Volunteer Bias: A form of sampling bias where volunteers are more motivated, potentially skewing results.

Sampling Techniques

• Opportunity Sampling: Recruiting the most convenient individuals, quick but limited generalizability.
• Random Sampling: Every individual has an equal chance of selection, unbiased but time-consuming.
• Stratified Sampling: Subgroups are identified and randomly sampled proportionally to their frequency in the population, easier to generalize but time-consuming.
• Systematic Sampling: Selecting every nth person from a list, unbiased but not truly random if the n is not used.
• Volunteer Sampling: Participants choose to take part, offering variety but susceptible to volunteer bias and difficult to generalize.

Types of Data

• Primary Data: Information gathered firsthand, designed for the specific study but time-consuming.
• Secondary Data: Information gathered from previous studies, inexpensive but may not fit the study's needs precisely.
• Quantitative Data: Measurable data expressed numerically, easy to analyze but potentially oversimplifying reality.
• Qualitative Data: Descriptive data expressed in words, providing detailed information but challenging to analyze and identify causal relationships.

Ethical Issues in Research

• Informed Consent: Participants must be fully informed about the research and their role, including their rights to withdraw.
• Deception: Participants are not told the true aims of the study, justified if benefits outweigh risks and full debriefing is provided.
• Right to Withdraw: Participants can choose to leave the study if they feel uncomfortable, but limitations may exist regarding timing and other concerns.
• Protection from Harm: Participants should not experience negative physical or psychological effects, assessed carefully as potential harm may not be apparent initially.
• Confidentiality: Personal information shared during research is protected, potentially using numbers, initials, or false names to preserve anonymity.
• Privacy: Participants' right to control information about themselves, including their personal space and activities, requiring informed consent unless in public spaces where the definition can be ambiguous.

Observational Techniques

• Controlled Observation: Observing behavior in a structured and organized environment.
• Naturalistic Observation: Observing behavior in a natural setting without intervention.
• Covert Observation: Participants are unaware they are being observed.
• Overt Observation: Participants are aware they are being observed.
• Non-Participant Observation: The observer is separate from the participants.
• Participant Observation: The observer actively participates in the task.
• Interobserver Reliability: Agreement between two or more observers on their observations.
• Observer Bias: The observer's expectations influencing their observations.

Observational Design

• Unstructured Observation: The observer records any relevant behavior without a predefined system.
• Structured Observation: The observer uses a system to organize observations, potentially using behavioral categories or event sampling.
• Behavioral Categories: Target behaviors are broken down into specific and operationalized categories, for example the Meltzoff and Moore study (1977) analyzed facial expressions.
• Event Sampling: Recording the frequency of target behaviors.
• Time Sampling: Recording behavior at predetermined intervals.

Self-Report Techniques

• Structured Interview: Questions are pre-designed and standardized for consistent administration, but may limit responses and introduce interviewer bias.
• Unstructured Interview: General questions are followed by participant-guided questions, offering more detailed information but requiring skilled interviewers.
• Questionnaires: Standardized, efficient, and easily repeatable, but subject to social desirability bias and potential response limitations.
• Interviewer Bias: The interviewer's expectations influencing participant behavior.
• Social Desirability Bias: Participants distort their responses to portray themselves favorably.

Self-Report Design

• Closed Questions: Predetermined answer choices, efficient but may not capture nuanced responses.
• Open Questions: Allow participants to provide their own answers, promoting detailed information but making comparison difficult.
• Filler Questions: Unrelated questions used to distract from the study's main purpose, potentially reducing social desirability bias.

Correlations and Mathematical Skills

• Correlational Hypothesis: States a relationship between two measurable variables.
• Correlation Coefficient: A number (between -1 and +1) representing the strength and direction of the relationship between two variables.
• Significant Figures: Simplified representation of long numbers using powers of 10.
• Measures of Central Tendency: Mean, median, mode.
• Measures of Dispersion: Range, standard deviation.
• Normal Distribution: A symmetrical bell-shaped distribution of data.
• Skewed Distribution: A distribution with one tail longer than the other, positive if skewed to the left and negative if skewed to the right.

Case Studies and Content Analysis

• Case Study: An in-depth study of an individual, institution, or event, providing rich insights but limited generalizability (e.g., Phineas Gage).
• Content Analysis: An observational study examining behavior indirectly through visual, written, or verbal materials.
• Thematic Analysis: Organizing behaviors extracted from content analysis into categories for analysis.

Reliability

• Test-Retest Reliability: Administering the same test or interview to the same participants on separate occasions to assess consistency of results.
• Inter-Observer Reliability: Agreement between two or more observers on their observations, potentially improved by clearly operationalized behavioral categories and training.

Concurrent Validity

• Compares an existing test or questionnaire with a new one

Face Validity

• Concerns how well test items match the test's intended purpose

Temporal Validity

• Evaluates how well research findings can be generalized beyond a specific study's time period

Probability

• A numerical measure indicating the likelihood of specific events occurring

Null Hypothesis

• Assumes no relationship exists between variables in a population

Alternative Hypothesis

• A testable statement proposing a relationship between two or more variables

Type 1 Error

• Incorrectly rejecting a true null hypothesis

Type 2 Error

• Incorrectly accepting a false null hypothesis

Features of Science

• Employs the empirical method for evidence-based testing and observation
• Aims for objectivity, minimizing bias
• Stresses replicability of findings for verification
• Develops theories to explain facts and generate testable predictions
• Employs falsifiability to challenge null hypotheses and confirm alternative hypotheses
• Accommodates paradigm shifts for revolutionary scientific progress
• Incorporates peer review as part of its process, relying on independent experts to evaluate research quality

Peer Review

• Independent experts assess research quality, contributing to:
  • Funding allocation
  • Publication decisions
  • University department rankings

Psychology & Economy

• Psychology can play a key role in economic decision-making and avoiding irrational thinking
• Provides insights for companies to improve employee well-being and optimize performance

Research Report Structure

• Abstract: Concise summary of study aims, hypotheses, methods, and results (around 150 words)
• Introduction: Presents background information, relevant literature, research aims
• Method: Outlines research methods, designs, participants, sampling, materials, procedures, and ethical considerations
• Results: Reports findings using descriptive and inferential statistics, detailing qualitative data
• Discussion: Interprets results, addresses limitations, discusses implications
• References: Lists all cited sources