Week 7/8 - Parametric Statistics

Question 1

Random sampling error

Answer 1

Random factors cause a difference between sample and population (fix by increasing sample size)

Question 2

Non-experimental t-tests

Answer 2

Cross-sectional, observation

Question 3

Experimental t-tests

Answer 3

Normally distributed, control vs experimental groups

Question 4

Random variation

Answer 4

Expected difference in values

Question 5

Systematic variation

Answer 5

Selection biases (sample not random)

Question 6

Systematic error

Answer 6

Bias causes difference in sample from population (fix by using representative sample)

Question 7

T-test

Answer 7

2 groups, scale DV

Question 8

Inferential statistics

Answer 8

Shows if difference is due to IV or chance

Question 9

Region of rejection

Answer 9

Reject H0 if z-score is in top and bottom 2.5% of distribution

Question 10

P-value

Answer 10

If t-value is high, p-value is low

Question 11

Paired t-test

Answer 11

1 sample group does test twice

Question 12

Repeated measures t-test

Answer 12

See if 2 measures of DV differ significantly (for pre/post tests)

Question 13

Statistical power increases when…

Answer 13

1. low SD
2. high group difference
3. big sample size

Question 14

Effect size

Answer 14

Magnitude of effect

Question 15

Cohen’s D

Answer 15

D>0.2 small while D>0.8 is large