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Psychology as a Science: Features, Paradigms, Reports and Validity

Science gains knowledge through a cycle: a theory leads to a hypothesis, a test, and data that support or change the theory. Key features are empiricism, objectivity, replicability, falsifiability and theory construction. Kuhn argued that sciences work inside a shared paradigm and change through paradigm shifts when anomalies pile up; psychology may still be pre-paradigmatic. Research is shared through peer review and a report with set sections: abstract, introduction, method, results, discussion and references. Good research must be reliable (consistent) and valid (measuring what it claims), and there are several types of each.

🎬 Step-by-step story

  1. Science works in a cycle. A theory gives a hypothesis, a test checks it, and the data support the theory or change it.
  2. A scientific claim must be falsifiable. Many white swans cannot prove "all swans are white", but one black swan proves it false.
  3. Normal science builds inside a shared paradigm. When results that do not fit pile up, the old view falls and a new paradigm takes over.
  4. A research report has six parts: abstract, introduction, method, results, discussion and references.
  5. Reliable means consistent: the darts land close together. Valid means accurate: they land on the true centre.
  6. Free play: change the spread and the bias. See when a measure is reliable, valid, both or neither.

Tip: drag the 3D scene to turn it. Use two fingers to zoom.

πŸ€” Common doubts, cleared

If science cannot prove theories true, why trust it?

Theories that survive many tests that could have falsified them are strongly supported. Step 1 shows the cycle repeating and refining.

Is psychology really a science?

Much of it uses empirical, replicable, falsifiable methods. Some areas, like psychodynamic ideas, are hard to falsify. Step 2 shows the falsifiability test.

Why do some results not replicate?

Small samples, publication bias and subtle changes in method. Replication failures can be early anomalies, as in step 3.

What goes in the abstract versus the discussion?

The abstract is a short summary of everything; the discussion interprets the results and their limits. Step 4 shows their order.

Can a test be valid but unreliable?

Not truly: if scores jump around, you cannot be sure they measure the right thing. Raise the spread in the free play and see validity fail too.

What is the difference between internal and external validity?

Internal: did the IV really cause the change inside the study? External: do results apply to other people, places and times? Step 5 shows accuracy on the target.

Features of science

Science is a way of gaining knowledge by testing ideas against evidence.

Paradigms and paradigm shifts

Thomas Kuhn said a mature science has a paradigm: a shared set of assumptions and methods that most scientists in the field accept.

Kuhn suggested psychology may be pre-paradigmatic, because it has several competing approaches (biological, behaviourist, cognitive and others) rather than one shared paradigm. Others argue the cognitive approach, or cognitive neuroscience, is close to one.

Peer review and reporting research

Peer review means experts in the same field check a study before it is published. They judge the method, the analysis and whether conclusions follow from the data. It filters out poor work, but it can be slow, reviewers may be biased against new ideas, and there is publication bias towards positive results.

A scientific report has standard sections:

  1. Abstract: a short summary (aim, method, results, conclusion) of about 150–200 words.
  2. Introduction: past research leading to the aims and hypotheses.
  3. Method: design, participants and sampling, materials, procedure and ethics, in enough detail to replicate.
  4. Results: descriptive statistics, graphs and inferential tests.
  5. Discussion: what the results mean, links to past research, limitations and ideas for future research.
  6. Referencing: full details of every source, in a standard format.

Types of validity and reliability

Validity means a study or test measures what it claims to measure, and results are genuine.

Reliability means consistency. Test-retest: the same person gets similar scores on two occasions. Inter-observer: two observers record the same behaviour in the same way (correlation above +0.80). A measure can be reliable but not valid, but it cannot be truly valid if it is unreliable.

Try it: test your own measure

Weigh a book on a kitchen or bathroom scale five times. Are the readings close together (reliable)? Then weigh something whose mass you know, like a 1 kg bag of rice. Is the scale right (valid)? Match your result to a target in the 3D free play.

Key formulas and definitions

Worked examples

1. A personality test gives a student very different scores one week apart. What is the problem?

Poor test-retest reliability: the test is not consistent over time.

2. A lab memory study uses lists of nonsense syllables. Why might it lack ecological validity?

Remembering nonsense syllables in a lab is unlike everyday memory, so results may not generalise to real-life settings.

3. A new anxiety questionnaire correlates +0.86 with an established one. What type of validity does this show?

Concurrent validity: it agrees with a trusted test taken at the same time.

Common mistakes

Practice quiz

1. A claim that can be proved wrong by evidence is:
2. Kuhn's term for a shared set of assumptions in a science is:
3. Which report section gives enough detail to repeat the study?
4. Validity that concerns other settings is called:
5. Darts that land close together but away from the centre are:

Practice: answer these yourself

Type or choose your answer, then press Check. Use a hint if you are stuck; the full solution appears after you answer.

Frequently asked questions

What are the main features of science in psychology?

Empiricism, objectivity, replicability, falsifiability, theory construction and hypothesis testing, and working within paradigms.

What is the difference between reliability and validity?

Reliability is consistency of results; validity is whether the study measures what it claims and results are genuine.

What are the sections of a psychology report?

Abstract, introduction, method, results, discussion and references.

Where this is taught

England (GCSE, A level)Year 134.2.3 Research methods (A-level extension)

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