The Scientific Method

Question 1

What are the five steps of the scientific method?

Answer 1

1. Observation and description of phenomena (ask a question)
2. Hypothesis formulation
3. Predict quantitative results of observations or existence of other phenomena
4. Perform experimental tests of predictions
5. Quantitative analysis and conclusion

Question 2

What is the difference between the observational method and the experimental method?

Answer 2

Observational: observations are uncontrolled, relationships and hypothesis are formulated at the end. Investigator does not interfere.
Experimental: observations are controlled, hypothesis and relationships are formulated at the start. Investigator tries to control environment where the hypothesis is tested.

Question 3

What are the pros of experimental studies?

Answer 3

They have more validity
Able to determine causality
Randomised and blinded - means a smaller chance of bias

Question 4

What are the cons of experimental studies?

Answer 4

May require more resources (money and time)
Ethical concerns for some exposures
Difficult if outcome studied is rare

Question 5

What are the pros of observational studies?

Answer 5

May need less resources (money and time)
Less ethical concerns (observing, not experimenting)
Good if outcome is rare

Question 6

What are the cons of observational studies?

Answer 6

Less validity as difficult to determine causality
No randomisation or blinding

Question 7

What are the steps of the experimental process?

Answer 7

1. State the problem or question
2. Choose which variables will be measured and/or manipulated, and the methods and instruments with which you’ll do it
3. Determine the controls
4. Design the experiment/study
5. Collect data
6. Analyse the data

Question 8

What are the possible outcomes of research?

Answer 8

Theory or law of nature ‘created’.
Hypothesis needs to be modified or rejected.
Predictive power of the hypothesis/theory increases.
Theory is disproved.
New observation conflicts with long-standing theory.

Question 9

What are the possible pitfalls of research?

Answer 9

Bias - preference for a particular outcome (must not affect results or their interpretation).
Hypothesis is confused with the explanation.
Data which doesn’t support the hypothesis is ignored/ruled out.
Systematic errors are not estimated quantitatively .
Sample is too small - leads to the experiment being underpowered (not reliable due to small size).

Question 10

What is the definition of a hypothesis?

Answer 10

A limited statement of cause and effect in a specific situation. Can also refer to knowledge before experimental work has been performed.

Question 11

What is the definition of a model?

Answer 11

Hypothesis with limited validity

Question 12

What is a theory/law?

Answer 12

Hypothesis (or group of) which has been confirmed through repeated experimental tests

Question 13

What is the null hypothesis?

Answer 13

A hypothesis which can be disproven (opposite to the hypothesis)

Question 14

What is the difference between dependent and independent variables?

Answer 14

Dependent: response due to a change (behavioural, physiological or self-report [e.g. mood or satisfaction])
Independent: manipulated by experimenter (treatment type, treatment factors [e.g. length or location], experimental manipulations)

Question 15

Why is the scientific method helpful?

Answer 15

Results should explain something (even if not what you were looking for).
Helps distinguish between correlation and causation.
Gives empiricism: knowledge is verified through evidence from observation.
Gives determinism: discovers laws and causes.
Allows for scepticism.

Question 16

What is deductive reasoning?

Answer 16

Takes information from the general case to a specific case (e.g. all birds have feathered wings, sparrows have feathered wings, so sparrows are birds)

Question 17

What is inductive reasoning?

Answer 17

Takes information from specific cases to a general principle (e.g. sparrows are birds, they have wings and can fly. Other types of birds have wings and can fly, so all types of birds can fly)

Question 18

What is an inductive leap?

Answer 18

Generalisation made from many cases to saying that the observation is true in all cases (unlikely to be true)

Question 19

When does the scientific method work best?

Answer 19

Phenomenon can be isolated by eliminating (or accounting for) extraneous factors, the system can be repeatedly tested after making small, controlled changes to it.