Psychology: Science, Biases and Theories

• Psychology uses systematic observation, experimentation, and empirical evidence.
• Science differs from personal experience, tradition, and authority through objective, repeatable methods that reduce bias.
• Pseudoscience lacks falsifiability, relies on anecdotal evidence, and does not follow rigorous scientific methods.

Cognitive Biases

• Confirmation Bias: Seeking information confirming preexisting beliefs and ignoring contradictory evidence.
• Hindsight Bias: Believing an outcome was predictable after it has already occurred.
• Anchoring Bias: Over-relying on the first piece of information encountered.

Scientific Theory

• A well-substantiated explanation based on empirical evidence.
• Must be falsifiable, testable, and supported by research.

Scientific Hypothesis

• A specific, testable prediction derived from a theory.
• Must be falsifiable and measurable.
• Example: "People who sleep at least 8 hours perform better on memory tests than those who sleep less than 5 hours."

Control Groups

• Control groups help isolate the effect of the independent variable by providing a comparison.
• Control groups eliminate confounding variables and placebo effects.
• Example: A control group receiving a placebo in drug trials helps determine if the drug’s effects are real or due to psychological expectations.

Sections of a Scientific Paper

• Abstract: Brief summary of the study, including objectives, methods, results, and conclusions.
• Introduction: Background information, research question, hypotheses, and significance of the study.
• Methods: Detailed explanation of participants, procedures, materials, and research design for replication.
• Results: Presentation of data, statistics, and key findings without interpretation.
• Discussion: Interpretation of results, limitations, implications, and future research suggestions.
• References: List of all sources cited in APA format.

APA Style

• In-text citation format: (Author, Year) or (Author, Year, p. #) for direct quotes.
• Reference list should be alphabetized and include author(s), year, title, source, and DOI (if available).
• Example In-text citation: (Smith, 2020).
• Example Reference: Smith, J. (2020). Title of the book. Publisher.

Reliability

• Reliability refers to the consistency of measurement.
• Types of reliability: test-retest, inter-rater, internal consistency (Cronbach’s alpha).
• Example: A reliable IQ test will produce similar scores for the same individual over time.

Validity

• Validity refers to whether a test measures what it claims to measure.
• Types of validity: content validity, construct validity, criterion validity.
• Example: A depression scale should accurately measure depression, not anxiety.

Ethical Guidelines in Research with Human Subjects

• Informed Consent: Participants must be fully informed about the study and voluntarily agree to participate.
• Confidentiality: Protecting participants’ personal information.
• Deception: Only allowed if necessary and must be followed by debriefing.
• Right to Withdraw: Participants can leave the study at any time without penalty.
• Minimizing Harm: Researchers must avoid physical or psychological harm.

Types of Measurement Scales

• Nominal: Categorical (e.g., gender, ethnicity).
• Ordinal: Ranked order without equal intervals (e.g., education level).
• Interval: Equal intervals, no true zero (e.g., temperature in Celsius).
• Ratio: Equal intervals, true zero (e.g., weight, height).

Variables

• Independent Variable (IV): The manipulated factor in an experiment.
• Dependent Variable (DV): The measured outcome.
• Confounds: Uncontrolled variables that may influence the DV.
• Constructs: Abstract concepts measured in research.
• Operationalization: Defining a construct in measurable terms.