Stats class 2

Question 1

What is an experiment?

Answer 1

Randomisation, differences between the groups are because of our manipulation. Experiments let you infer causation.

Question 2

Bradford Hill criteria

Answer 2

1. Strength
2. Consistency
3. Specificity
4. Temporality
5. Biological gradient
6. Plausibility
7. Coherence
8. Experience
9. Analogy

Question 3

Case control

Answer 3

Find a group of people exposed to a disease (oral cancer) and then find a group of people who haven’t been exposed to the disease and then see if they have been exposed to something to cause this (tobacco)

Question 4

Spurious correlations: the third variable problem

Answer 4

This graph makes it look like these two variables are linked. However it’s not considering the ‘third variable’ that is causing the increase in both of these factors.

The third variable in this case is ‘heat’.

Question 5

Disinformation vs misinformation

Answer 5

Disinformation = lying
Misinformation = being wrong and telling people

Question 6

Deductive reasoning

Answer 6

General to specific
“All bacteria need oxygen, this sample is bacteria, therefore it needs oxygen.”

Question 7

Falsifiability

Answer 7

Disprove deductive reasoning

“all bacteria need oxygen”, finding a sample of bacteria that don’t need oxygen.

Question 8

Inductive reasoning

Answer 8

Specific to general
“This bacteria needs oxygen, all the bacteria I’ve observed need oxygen, therefore all bacteria need oxygen”

These arguments are widely used in science, inductive arguments cannot be falsified and so they are intrinsically less robust.

Question 9

Gold standard in primary research

Answer 9

Experiments