statistics

Question 1

what are the 3 factors to choose a statistical test ?

Answer 1

1. difference or correlation
2. Design measure
3. Levels of measurement

Question 2

What is nominal data ?

Answer 2

Data is represented in the form of categories

Question 3

What is ordinal data?

Answer 3

Data is ordered in some way eg a rating scale where scores are converted into ranks

Question 4

What is interval data?

Answer 4

Based on numerical scales that include precise units eg time, temperature, weight

Question 5

What central tendency + dispersion is used for nominal data?

Answer 5

mode
n/a

Question 6

what central tendency + dispersion is used for ordinal data?

Answer 6

median
range

Question 7

what central tendency + dispersion is used for interval data?

Answer 7

mean
sd

Question 8

When do you use chi squared?

Answer 8

Nominal
Unrelated
Test of association or correlation OR difference

Question 9

When do you use Mann Whitney?

Answer 9

Test of difference
Ordinal
Unrelated

Question 10

When do you use unrelated t test

Answer 10

test of difference
Interval
unrelated

Question 11

When do you use the sign test?

Answer 11

Related design
Nominal data
Test of difference

Question 12

When do you use wilcoxon?

Answer 12

Test of difference
Related
Ordinal

Question 13

When do you use spearman’s rho?

Answer 13

Test of association or correlation
Ordinal data

Question 14

When do you use related t test

Answer 14

Test of difference
Related design
Interval

Question 15

When do you use Pearsons r ?

Answer 15

Test of association or correlation
Interval

Question 16

what does the null hypothesis state?

Answer 16

no difference between conditions

Question 17

what is the level of significance - definition and value?

Answer 17

point at which the researcher can claim to have discovered a large enough difference or correlation within the data so they can accept alternative

0.05

Question 18

what is the difference between calculated and critical value ?

Answer 18

calculated - observed value
critical - tells us whether or nor we can reject the null hypothesis and accept alternative

Question 19

what are the 3 criteria to use tables of critical values?

Answer 19

One tailed or two tailed
No of ppts in the study
Significance level

Question 20

What is the N value on the table of critical vales?

Answer 20

no of ppts

Question 21

what is a type I error?

Answer 21

false positive as a correlation does not exist so they should have accepted null hypothesis instead of reject

Question 22

what is a type II error?

Answer 22

false negative is we should reject null hypothesis and accept alternative