Approaches to data analysis

Question 1

What is the difference between descriptive and inferential statistics?

Answer 1

Descriptive statistics summarise data by reducing a large amount of data to a small representation.

Whereas inferential statistics involve the analysis of whether the findings are significant or not. e.g the difference or the relationship is significant. If they are significant enough they can be applied to larger populations.

Question 2

What is the difference between a type 1 and type 2 hypothesis

Answer 2

type 1: incorrectly finding a significant effect
type 2: incorrectly finding there is no significant effect.

Question 3

What is the p value and alpha level

Answer 3

p= probability of making a type 1 error.
In psych we use alpha level p= 0.05
If the effect is bigger, then you are less likely to make a type 1 error

Question 4

What are degrees of freedom (df)

Answer 4

number of participants - 1
or conditions - 1
Having more of them is better so you are less likely to make a mistake.

Question 5

How to tell is a difference is significant

Answer 5

Take the calculated value and the critical value, if the calculated is greater than, it is significant

Question 6

Why is it better to have more degrees of freedom

Answer 6

Because it means you critical value will be lower this means the effect will not need to be so significant. This is because with a larger sample size, results are likely to apply to the population.

Question 7

4 pieces of information needed to calculate critical value using table

Answer 7

1) df
2) alpha level
3) calculated t value
4) 1 or 2 tailed hypothesis

Question 8

What is the APA format

Answer 8

t (5) = 2.6 p < .050

(statistic code)
(df)
(statistics calculated value)
(p value)