PSY2012 COREFSU QUIZ STUDY GUIDE

r-value +0.85

Strong positive correlation (as r gets closer to +1, the relationship is stronger and in the same direction).

r-value -0.15

Weak negative correlation (close to 0 means weak; negative sign means opposite directions).

r-value +0.45

Moderate positive correlation (mid-range strength, same direction).

r-value -0.92

Strong negative correlation (close to -1, strong but opposite directions).

Correlation and causation

No; ice cream sales and drowning rates correlate in summer, but heat (third variable) causes both.

r = +0.70 between study time and exam scores

No; a third variable (e.g., motivation) could cause both, or reverse causation (better students study more).

p-value of 0.03

The result is statistically significant; there is <5% chance the result occurred by random chance if the null is true.

p-value of 0.12

The result is not statistically significant; we fail to reject the null (could be due to chance).

Reliable psychological measurement

Consistency of results across repeated measures (e.g., test-retest, inter-rater, internal consistency).

Valid psychological measurement

It measures what it claims to measure (e.g., content, criterion, construct validity).

Importance of reliability and validity

Unreliable measures give inconsistent data; invalid measures give wrong conclusions about the construct.

Internal validity

Results are due to the IV (causal confidence).

External validity

Results generalize to other people/settings.

Threatened validity in therapy study

External validity (may not apply to real-world clinical populations).

Random assignment

Each participant has an equal chance of being placed in any group (e.g., via random number generator).

Importance of random assignment

Balances confounding variables across groups, increasing internal validity and causal claims.

Sample characteristics

Allows assessment of generalizability and identification of sample-specific effects.

External validity limitation

Findings may not apply to children, older adults, or non-students when the study uses only 18-22-year-old college students.

Causal relationships

True experiments with manipulation, random assignment, and control can determine causal relationships.

Establishing causality

1. Covariation (correlation), 2. Temporal precedence (IV before DV), 3. Elimination of alternative explanations (via control/random assignment).

Conceptual definition of depression

Depression is a persistent sad mood lasting >2 weeks.

Operational definition of depression

Depression measured by a score >20 on the Beck Depression Inventory.

Independent variable in caffeine study

Caffeine dosage (manipulated by researcher).

Dependent variable in caffeine study

Reaction time (measured outcome).

Replicating a study

Repeating the study (same methods) to see if the same results occur.

Replication and confidence

Rules out flukes, errors, or context-specific findings; consistent results suggest robustness.

Theory vs. hypothesis

Theory: broad, organized set of principles explaining phenomena; Hypothesis: specific, testable prediction derived from a theory.

Characteristics of a good theory

Falsifiable, parsimonious, explains existing data, generates new testable hypotheses, supported by evidence.

Ethical practices in human research

Informed consent, debriefing, minimization of harm, confidentiality, right to withdraw.

Deception in research

Full debriefing afterward, explaining deception and allowing withdrawal of data.

Correlation (r-values)

r ranges from -1 to +1; |r| > .70 = strong, .30-.70 = moderate, < .30 = weak; positive (+) = same direction, negative (-) = opposite direction.

Correlation and causation

No; alternatives: third variable (confound), reverse causation, bidirectional causation, or coincidence.

p-value

p = probability of data if null is true; significant (p ≤ α, usually .05) = reject null, unlikely due to chance; non-significant (p > α) = fail to reject null, may be chance.

Reliable measurement

Reliable = consistent (test-retest, inter-rater, internal); Valid = measures intended construct (content, criterion, construct); Matter: unreliable = noisy data, invalid = wrong conclusions.

Internal validity

Internal = confidence that IV caused DV change (ruling out confounds); External = generalizability to other people, settings, times.

Random assignment

Random assignment = each participant equal chance to any group (e.g., coin flip, random number); Important: balances confounds, supports causality.

Study sample characteristics

Describe to assess generalizability and detect sample-specific effects; Sample limits: WEIRD samples (Western, Educated, Industrialized, Rich, Democratic) may not apply broadly.

True experiment

True experiment; Needs: (1) manipulate IV, (2) random assignment, (3) measure DV, (4) control extraneous variables.

Operational definition

Conceptual = abstract meaning (e.g., "anxiety is excessive worry"); Operational = measurable indicator (e.g., "anxiety = score > 10 on GAD-7").

Independent variable

IV = manipulated/predicted cause; DV = measured outcome; Example: IV = therapy type (CBT vs. waitlist), DV = depression score reduction.

Replicating a study

Replicate = repeat study with same methods; Increases confidence by ruling out chance, error, or context-specific effects.

Theory vs hypothesis

Theory = broad explanatory framework; Hypothesis = specific testable prediction; Good theory: falsifiable, parsimonious, explains data, generates hypotheses, empirically supported.

Ethical practices in research

IRB approval, informed consent, voluntary participation, right to withdraw, confidentiality, minimize harm, debriefing (especially if deception used).