Lecture #3: The Brain + Experiments

Question 1

Null hypothesis (Ho)

Answer 1

No difference between control group and IV.

Question 2

Alternative hypothesis (Ha)

Answer 2

There is a difference between control group and IV

- There is an effect

Question 3

p-value

Answer 3

The probability that the result is due to chance.

• Lower value = lower probability of chance.
• P-value threshold is set before testing so anything > p-value is statistically significant

Question 4

Sample size and effect

Answer 4

• More likely to see the effect if larger sample size.

- Larger effect = more statistical power

Question 5

Strength of the effect

Answer 5

• the strength of the relationship between variables = effect size.
  § You can have differing differences
  § e.g. 3 treatments = statistically significant, but have differing effects (small effect/weak relationship, intermediate effect, large effect/strong relationship).