PSYCH307 – Lecture 1 Notes
Course Overview
Purpose and Emphasis
PSYCH307 introduces a range of research theories and methods to strengthen expertise in psychological research.
Strong emphasis on quantitative research; expect extensive work with statistics.
Administrative Essentials
Course outline, announcements, assignment portals, and laboratory sign-ups are all housed on Moodle – check it frequently.
All assignments are submitted through Moodle and Turnitin is used for plagiarism checks.
Core Resources
Main statistics text: Field (2018, 5th ed.) Discovering Statistics Using IBM SPSS Statistics (earlier editions acceptable).
APA Publication Manual (7th ed.) is compulsory; earlier editions are not acceptable.
Additional readings will be released as the course progresses.
Timetable
Lectures: Monday, 1 – 3 pm
• Hamilton: Room L.G.03
• Tauranga: Room TCBD.3.06
Attendance is highly encouraged.Laboratories (Teams-based workshops) begin Week 2.
• Some labs have an instructor; others are drop-in.
• Sign-up opens today at 4 pm on Moodle under “Laboratory Signup.”
• Labs focus on statistical analyses required for the lab-report assessments.
Assessments (No Final Exam)
Task | Weight | Notes |
|---|---|---|
Online Test 1 | ||
Online Test 2 | ||
Lab Report 1 | Raw data provided | |
Lab Report 2 | Raw data provided | |
Total |
General Assessment Advice
Start early, avoid last-minute rush.
Collaborate for understanding but submit your own work.
Communicate problems early—staff can only help if they know.
Engage actively; learning is greatest when you do.
Revision of Research Methods
Inspirational Quotes
“Research is to see what everybody else has seen, and to think what nobody else has thought.” — Albert Szent-Györgyi
“There is nothing as practical as a good theory.” — Kurt Lewin (1943/1951)
The Research Process (Cycle)
Observation of behaviour/phenomenon.
Theory generation (or theory testing).
Hypothesis formation from the theory.
Research design & data collection.
Data analysis & interpretation.
Theory refinement / new hypotheses → back to Step 3.
Example: Human Response to Soundscapes
Theory: Natural sounds are restorative; environmental noise is harmful.
Medvedev et al. (2015): Two studies measured physiological and psychological responses after stress/rest while manipulating soundscapes.
Results loop back to theory: supported? falsified? If falsified, refine the theoretical model and restart the cycle.
Stokes’ Quadrant Model of Scientific Research
CONSIDERATION OF USE? ─────────────────────► YES
│ Pure Applied (Edison)
QUEST FOR │
FUNDAMENTAL │ Use-Inspired Basic (Pasteur)
UNDERSTANDING?│
│ Pure Basic (Bohr)
▼ NO
Bohr quadrant: Pure basic research, e.g., atomic structure.
Pasteur quadrant: Simultaneously seeks understanding and use (e.g., vaccination).
Edison quadrant: Pure applied, focused on utility.
Most psychological projects sit somewhere between quadrants, balancing theoretical insight and practical application.
Key Topics in Research Logic
Inductive vs Deductive Reasoning
Induction: Build theory from observations (data → theory).
Deduction: Start with theory, derive hypotheses, and test with data (theory → data).
Real-world studies usually blend both; quantitative work leans deductive, qualitative leans inductive.
Correlation vs Causation
Correlation:
Occur together but A may not cause B.Causation:
Requires temporal precedence, covariation, and elimination of alternatives.
Independent vs Dependent Variables
Independent Variable (IV): Manipulated or classified cause.
Dependent Variable (DV): Measured outcome.
Manipulation grants control—researcher sets IV levels, enabling “switch on/off” tests of causal effects.
The Third-Variable Problem
Apparent IV → DV relationship may be spurious, produced by a hidden variable.
Examples
Violent video games ↔ aggression; stress could cause both.
Population density ↔ crime; socioeconomic status (SES) could be the real driver.
Third Variable vs Confound vs Intervening (Mediator)
Type | Role | Threat to Validity | Illustration |
|---|---|---|---|
Third Variable | External factor related to both IV & DV | Creates misleading associations | |
Confounder | Extraneous variable systematically varying with IV | Biases causal inference | |
Mediator (Intervening) | Mechanism through which IV affects DV | Clarifies how effect occurs |
(For entertainment: “Pirates vs Global Warming” – a famous spurious correlation.)
Experimental vs Non-Experimental Designs
Experiments:
• Manipulation of IV
• Control of extraneous variables (random assignment, control groups)
→ can establish causation.Non-experimental (observational): Limited to correlations; useful when manipulation is impossible, unethical, or when seeking ecological validity.
Why Still Use Observational Methods?
Ethical/practical constraints (e.g., cannot assign sex or force smoking).
Pilot data to discover potential causal pathways.
Study behaviour in natural contexts.
Validity
Measurement Validity
Face Validity: Superficial appearance—does the measure look right?
Construct Validity (umbrella term): Degree to which a test truly measures the theoretical construct.
Convergent Validity: Correlates with established measures of same construct.
Predictive Validity: Forecasts future behaviours/abilities.
Design Validity
Internal Validity: Confidence that DV changes are caused by IV manipulation; requires control of extraneous factors.
External Validity: Generalisability of findings beyond sample/setting.
The Trade-Off
High internal validity often uses tight lab control → may sacrifice realism.
High external validity (field settings) → harder to rule out confounds.
Reliability
Definition
Consistency or repeatability of a measurement.
A measure can be reliable but not valid, yet cannot be valid without being reliable.
Measurement Error Conceptualised
Greater error → lower reliability.
Scale Example
True weight .
Readings: , , indicate small random error.
Assessing Reliability
Test–Retest Reliability: Correlation between scores at Time 1 and Time 2.
Internal Consistency
• Split-Half: Correlate odd vs even items.
• Cronbach’s / McDonald’s : Average inter-item correlation—most widely reported.
Measurement in Experimental Research
Objective Quantification
Assign numbers or categories systematically to represent constructs.
Direct Measurement
Concrete variables: height, weight, speed.
Indirect (Psychometric) Measurement
Abstract constructs: stress, depression, coping; rely on questionnaires, ratings, behavioural indices.
Variables & Levels of Measurement
Discrete vs Continuous
Discrete Quantitative (Counts): Whole numbers (e.g., goals scored).
Qualitative/Categorical: Labels (gender, ethnicity) – numbers are mere codes.
Continuous Quantitative (Measures): Infinite gradations (height, reaction time).
Rule of Thumb: Counting → discrete, measuring → continuous.
Four Measurement Scales
Level | Key Properties | Can Order? | Equal Gaps? | True Zero? | Examples |
|---|---|---|---|---|---|
Nominal | Categories only | No | No | No | Eye colour, gender |
Ordinal | Rank order | Yes | No | No | Race placement, Likert satisfaction |
Interval | Equal intervals | Yes | Yes | No | , IQ |
Ratio | Interval + true zero | Yes | Yes | Yes | Height, age, reaction time |
SPSS merges Interval and Ratio into a single “Scale” variable type because analyses treat them similarly.
No Scale is “Better”
Choice depends on research design and operational definition.
Ethical, Practical & Real-World Connections
Ethical guidance (APA 7th ed.) underpins report writing, citation, and study conduct.
Understanding validity/reliability ensures fair assessment in applied settings (clinical, educational, organisational).
Differentiating correlation from causation prevents harmful policy decisions based on spurious links (e.g., violent games legislation).
Numerical & Statistical References
Assessment weighting: .
Reliability coefficients: Cronbach’s , McDonald’s (interpretation guidelines: acceptable, good, excellent).