# The Scientific Method

Psychology I · Research Techniques · https://tryals.app/learn/psychology-i/the-scientific-method

The **scientific method** is a systematic framework for building reliable knowledge, moving from an **observation** to a **research question**, a testable **hypothesis**, and empirical testing.

| Step | What happens |
|---|---|
| **Observation** | Notice a pattern or phenomenon |
| **Hypothesis** | Propose a testable explanation |
| **Prediction** | Derive a specific expectation |
| **Test** | Collect data via a study |
| **Conclusion** | Interpret the data |
| **Replication** | Independent repeat by others |

Per philosopher **Karl Popper**, a genuine hypothesis must be **falsifiable**: there must be a possible observation that could prove it wrong. Claims immune to all contradiction lie outside science.

## Logic and Structure

Scientific reasoning uses two directions of logic:

| Logic Type | Direction | Example |
|---|---|---|
| **Inductive** | Specific to general | Many white swans $\rightarrow$ all swans white |
| **Deductive** | General to specific | Theory $\rightarrow$ specific experiment |

A **theory** is a broad, well-supported explanatory framework, whereas a **hypothesis** is a specific prediction derived from it.

> **Pitfall:** Treating hypothesis and theory as interchangeable. In science, a **theory** is much stronger—backed by converging evidence—not a mere guess.

## Practice questions

6 of this lesson's 12 practice questions, with answers. The full set is in the app.

### 1. Put the stages of the scientific method in the order a researcher actually moves through them.

**Answer:**

1. Notice a pattern or phenomenon worth explaining (observation)
2. Propose a testable, falsifiable hypothesis to explain it
3. Derive a specific prediction the hypothesis commits you to
4. Run a study and collect data to test that prediction
5. Draw a conclusion, then invite others to replicate it

**Why:** Observation seeds a hypothesis, which yields a testable prediction, which a study checks, ending in a conclusion others can replicate. Deriving the prediction before committing to a hypothesis, or 'replicating' before concluding, would break the logic of the cycle.

Page: https://tryals.app/practice/psychology-i/the-scientific-method/put-the-stages-of-the-scientific-method-in-the-order-a-researcher

### 2. Select every statement that is TRUE about scientific reasoning.

A. A claim earns its scientific standing by ruling something out.
B. Independent replication strengthens confidence in a finding.
C. A claim that no evidence could ever contradict is the most scientific kind.
D. Deductive reasoning derives specific predictions from a general theory.
E. A theory is a weaker, more tentative claim than a single hypothesis.

**Answer:** A. A claim earns its scientific standing by ruling something out.; B. Independent replication strengthens confidence in a finding.; D. Deductive reasoning derives specific predictions from a general theory.

**Why:** Falsifiability, deduction (theory to prediction), and replication are all correct. A theory is stronger than a hypothesis, not weaker, and an unfalsifiable claim is unscientific rather than maximally scientific - the two false options embed the lesson's named traps.

Page: https://tryals.app/practice/psychology-i/the-scientific-method/select-every-statement-that-is-true-about-scientific-reasoning

### 3. *"Everyone has a hidden trauma; if you cannot recall it, that is the repression proving it."* Why does Popper's criterion reject this, when it sounds like a serious empirical claim?

A. Because it has never been supported by evidence in a controlled study
B. Because it is too vague about what counts as trauma to be operationalised
C. Because it concerns the unconscious, which cannot be measured directly
D. Because recalling a trauma confirms it and failing to confirms it too

**Answer:** D. Because recalling a trauma confirms it and failing to confirms it too

**Why:** Both branches confirm it, so no evidence can reach it. The trouble is not vagueness or lack of support but structure, a claim that cannot fail has said nothing about the world, and its apparent strength is the symptom.

Page: https://tryals.app/practice/psychology-i/the-scientific-method/everyone-has-a-hidden-trauma-if-you-cannot-recall-it-that-is-the

### 4. A researcher's theory predicts every score will land between 40 and 60. Six results come back: 44, 38, 52, 47, 55, 49. The researcher argues that five of six confirm the theory, so it is strongly supported. Why does Popper's criterion make the single 38 more informative than all five hits combined?

A. Because the theory forbade any score outside 40-60, and 38 happened.
B. Because a single measurement is more reliable than an average, so the outlier deserves the greater weight.
C. Because five out of six is not a large enough majority to support any scientific claim.
D. Because the theory should be revised to predict 35-60, at which point all six results confirm it.

**Answer:** A. Because the theory forbade any score outside 40-60, and 38 happened.

**Why:** A theory predicting 40–60 says nothing about the five results that fell there, one predicting 30–70, or nothing at all, would have accommodated them equally well. Those five could not discriminate a good theory from a loose one; the 38 could. Watch for the rescue: widen to 35–60 and the theory has stopped forbidding anything.

Page: https://tryals.app/practice/psychology-i/the-scientific-method/a-researchers-theory-predicts-every-score-will-land-between-40-and

### 5. "All swans observed so far have been white, so all swans are white" and "All swans are white, so the next swan will be white" use the same facts. Why can the second be certain while the first never is?

A. Because the first argument is about the past and the second is about the future, and predictions are inherently safer.
B. Because deduction uses larger samples than induction, and larger samples yield more certain conclusions.
C. Because deduction only unpacks the premise and induction reaches beyond.
D. Because induction is an unscientific form of reasoning that careful researchers avoid entirely.

**Answer:** C. Because deduction only unpacks the premise and induction reaches beyond.

**Why:** Deduction's certainty is bought by never venturing past the premise; induction ventures, and no number of white swans makes a black one impossible. The moral is not to abandon induction, every generalisation from data is inductive, but to hold it as a conjecture and put it at risk, since deduction *can* certify a falsehood the moment a counterexample turns up.

Page: https://tryals.app/practice/psychology-i/the-scientific-method/all-swans-observed-so-far-have-been-white-so-all-swans-are-white

### 6. A claim that no conceivable observation could ever contradict is, for that very reason, not a scientific hypothesis at all.

**Answer:** True

**Why:** True. Falsifiability requires that some possible observation could count against a claim; a claim immune to any disproof is unfalsifiable and therefore unscientific. Being un-contradictable is a disqualification, not a strength.

Page: https://tryals.app/practice/psychology-i/the-scientific-method/a-claim-that-no-conceivable-observation-could-ever-contradict-is-for