saptamana zece

Question 1

What are parametric tests?

Answer 1

Tests that have assumptions about distribution of populations sampled

Question 2

What are non-parametric tests?

Answer 2

No assumptions

Question 3

What are the assumptions of the parametric tests?

Answer 3

Level of data - must be at least interval/ratio
Interval - scale - with equal distances between each point on a scale
Ratio - scale with absolute zero

Question 4

What is another assumption?

Answer 4

Sample drawn at random from the population
That sample data should come from normally distributed population

Does not mean that data should be normally distributed, we are usually using samples that are too small to assess whether they are normal

Question 5

What is related t-test?

Answer 5

When we are looking at differences between 2 conditions = compare 2 groups

Question 6

When do we use related t-tests?

Answer 6

Interval data
DV has to be on a continuous scale - either interval or ration

Design: within groups (repeated)

Question 7

What are the assumptions of related t-test?

Answer 7

Random sampling
Normal distribution
interval/ration level data

Question 8

What is the non-parametric alternative?

Answer 8

Wilcoxon

Question 9

What do we report?

Answer 9

Means, SDs and N

T value, degrees of freedom and significance level

t(df) = t value, p = significant level (2-tailed)