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

25%25\%

Online Test 2

25%25\%

Lab Report 1

25%25\%

Raw data provided

Lab Report 2

25%25\%

Raw data provided

Total

100%100\%

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)

  1. Observation of behaviour/phenomenon.

  2. Theory generation (or theory testing).

  3. Hypothesis formation from the theory.

  4. Research design & data collection.

  5. Data analysis & interpretation.

  6. 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: Change in A    Change in B\text{Change in A} \; \longleftrightarrow \; \text{Change in B}
    Occur together but A may not cause B.

  • Causation: Change in A is necessary for Change in B\text{Change in A is necessary for Change in B}
    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
  1. Violent video games ↔ aggression; stress could cause both.

  2. 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

TemperatureIce-cream sales, Drownings\text{Temperature} \to {\text{Ice-cream sales, Drownings}}

Confounder

Extraneous variable systematically varying with IV

Biases causal inference

SmokingCoffee drinking (IV), Heart disease (DV)\text{Smoking} \to {\text{Coffee drinking (IV), Heart disease (DV)}}

Mediator (Intervening)

Mechanism through which IV affects DV

Clarifies how effect occurs

EducationJob skillsIncome\text{Education} \to \text{Job skills} \to \text{Income}

(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

Observed Score=True Score+Error\text{Observed Score} = \text{True Score} + \text{Error}

  • Greater error → lower reliability.

Scale Example

  • True weight =70.0kg=70.0\,\text{kg}.
    Readings: 69.569.5, 70.370.3, 69.869.8 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 α\alpha / McDonald’s ω\omega: 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

C^{\circ}\text{C}, 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: 2×25% (Tests)+2×25% (Lab Reports)=100%2 \times 25\% \text{ (Tests)} + 2 \times 25\% \text{ (Lab Reports)} = 100\%.

  • Reliability coefficients: Cronbach’s α\alpha, McDonald’s ω\omega (interpretation guidelines: 0.70\ge 0.70 acceptable, 0.80\ge 0.80 good, 0.90\ge 0.90 excellent).