Research methods and statistics

Question 1

Nominal data

Answer 1

When the DV is the number of participants in each category

Question 2

Ordinal data

Answer 2

When the data is a rank, position or rating

Question 3

Interval data

Answer 3

When the data is a real number/ measurement

Question 4

What is a measure of central tendency?

Answer 4

A measure of where the centre of the data is.

Question 5

Name the measures of central tendency

Answer 5

Mean, median, mode

Question 6

What are measures of dispersion?

Answer 6

Measures of how spread out the data is.

Question 7

Name measures of dispersion

Answer 7

Range, standard deviation

Question 8

Advantages and disadvantages of central tendency measures

Answer 8

Mean- most sensitive, but can be distorted by extreme values
Mode- Can easily identify most frequent value, but sometimes there is not a common value
Median-Not distorted by extreme values, but not good for small data sets

Question 9

Advantages and disadvantages of measures of dispersion

Answer 9

Range- quick to calculate, but doesn’t take into account all of the data
SD- most sensitive, but time consuming to calculate

Question 10

Define quantitative data

Answer 10

Data that is numerical or categorical, it has values

Question 11

Define qualitative data

Answer 11

Data with no numerical or categorical value, focused on detail.

Question 12

Normal distribution

Answer 12

Bell shaped curve, mode median and mean all in the same place

Question 13

Skewed distribution

Answer 13

Distributions leaning to one side. Mean median and mode in different places
Positive skew- tail to the right- mean and median higher than mode
Negative skew- tail to the left- mean and median lower than mode

Question 14

Type 1 error

Answer 14

Too lenient and reject null- false positive- due to low significance level (e.g 90% or 0.1)

Question 15

Type 2 error

Answer 15

Too strict and accept null- false negative- due to high significance level (e.g 99% or 0.01)

Question 16

Chi squared test requirements

Answer 16

Independent groups, difference, nominal

Question 17

Sign test requirements

Answer 17

Repeated measures, nominal, difference

Question 18

Spearman’s RHO

Answer 18

Correlation, ordinal (or both ordinal and interval)

Question 19

Pearson’s R

Answer 19

Correlation, not ordinal

Question 20

Mann-Whitney

Answer 20

Difference, ordinal, independent

Question 21

Wilcoxon

Answer 21

Difference, ordinal, repeated measures

Question 22

Unrelated t-test

Answer 22

Difference, interval, independent groups

Question 23

Related t-test

Answer 23

Difference, interval, repeated measures

Question 24

When to use tests with interval data? (Parametric)

Answer 24

When data is normally distributed and standard deviations are similar. Can use parametric tests usually anyway unless it is clear in q that data is skewed. Then use ordinal data tests.

Question 25

Formula for accepting rejecting hypothesis

Answer 25

State critical value and why (e.g, is two tailed, 5% significance, N=11). State if observed level is lower or higher. Therefore results significant/ not. Accept or reject.

Question 26

Is matched pairs repeated or independent measures?

Answer 26

Repeated.

Question 27

Chi squared table name?

Answer 27

Contingency table

Question 28

Df for chi squared?

Answer 28

(Columns of raw data (NOT TOTALS)-1) x (Rows of raw data-1)

Question 29

Df for Pearson’s R

Answer 29

Number of participants-2

Question 30

Df for unrelated t-test

Answer 30

Df= N1+N2-2

Question 31

Df for related t-test

Answer 31

Df= N-1