Choosing Statistical Test 1

Question 1

What must one ask when choosing a statistical test?

Answer 1

What is being tested? Are we comparing different samples for a point estimate (mean, median, frequency) - category 1
or are we demonstrating associations and relationships? - category 2

Question 2

For category 1 questions, what must we ask?

Answer 2

What is the nature of the point estimate - mean or proportional?
How many groups are being compared?
How many observations of similar nature are made in each subject - paired or unpaired (independent) observations?
Can we assume parametric distribution - is the data not continuous?

Question 3

Statistical tests for means

Answer 3

Parametric

Question 4

Statistic test for means of one group

Answer 4

One sample test

Question 5

Statistical test for means of two unpaired groups

Answer 5

Two sample test

Question 6

Statistical test of means of two groups which are paired?

Answer 6

Paired t test

Question 7

Statistic test for means with more than 2 groups which are unpaired

Answer 7

One way ANOVA

Question 8

Statistical test for means of more than 2 groups which are paired

Answer 8

MANOVA
Repeated measures ANOVA

Question 9

Statistical test for medians

Answer 9

Nonparametrical

Question 10

Statistical test for medians of one group

Answer 10

Sign test

Question 11

Statistical test for medians for two groups which are unpaired

Answer 11

Mann-Whitney U test

Question 12

Statistical test for medians of two groups which are paired

Answer 12

Wilcoxon rank sum test

Question 13

Statsistical test for medians of more than 2 groups which are unpaired

Answer 13

Kurska-Wallis test

Question 14

Statistical test for medians of more than 2 groups which are paired

Answer 14

Friedman test

Question 15

Statistical tests for proportions

Answer 15

Categorical

Question 16

Statistical tests for proportions of 2 groups which are unpaired

Answer 16

Chi square test

Question 17

Statistical test for proportions of two groups which are paired

Answer 17

McNemar test

Question 18

Statistical test for proportions of more than 2 groups which are unpaired

Answer 18

Log-linear or logistic regression

Question 19

What can parametric tests be used?

Answer 19

If at least one variable is quantitative and normally distributed

Question 20

Which parametric tests are used when comparing groups?

Answer 20

T-tests
ANOVA

Question 21

When are non-parametric tests used?

Answer 21

When either both dependent and independent variables are qualitative (nominal or ordinal)
or when variables are quantitative but not normally distributed

Question 22

What happens in nonparametric tests?

Answer 22

Ranks are compared

Question 23

What is the sign test?

Answer 23

Non-parametric test that compares median of a sample to median of the population

Question 24

What is the non-parametric equivalent of the one sample t test?

Answer 24

Sign test

Question 25

What is the Wilcoxon rank sum test used for?

Answer 25

Comparing two paired observations in nonparametric fashion

Question 26

What is Wilcoxon ranks um test equivalent to?

Answer 26

Paired t test

Question 27

What is Mann Whitney U test used for?

Answer 27

Independent observations in two groups

Question 28

What is Kruskal-Wallis

Answer 28

Non-parametric one-way ANOVA equivalent used for 3 or more groups

Question 29

Which statistical tests offer more robust analysis

Answer 29

Parametric

Question 30

Most commonly used method to transformation data from non-parametric to parametric?

Answer 30

Log transformation Square root transformation Square transformation Reciprocal transformation Logit transformation

Question 31

For what type of results does log transformation yield a normal distribution?

Answer 31

Right skew (positive)

Question 32

What is another name of normal distribution using log transformation?

Answer 32

Lognormal curve

Question 33

What can log transformation for right skew (positive) results do?

Answer 33

Yield normal distribution Linearize a nonlinear correlation with upward shift

Question 34

What does square root transformation do?

Answer 34

Normalise and linearize Stabilize variation

Question 35

What is square root transformation used for?

Answer 35

Normalising Poisson distributions

Question 36

What is reciprocal transformatino often used for?

Answer 36

Analysis of survival rates

Question 37

What is logit transformation often used for?

Answer 37

Distribution of proportions

Question 38

What does logit transformation do?

Answer 38

Linearizes a sigmoid curve CI may be difficult to interpret after transformation Geometric mean values may get distorted

Question 39

What is chi square test commonly used for?

Answer 39

Comparing frequency counts or proportions

Question 40

What type of test is Chi squared?

Answer 40

Non-parametric

Question 41

How does a Chi square test work?

Answer 41

Contingency table is constructed Rows and columns are mutually exclusive

Question 42

What is a contingency table?

Answer 42

A table whose contents are in frequencies

Question 43

Classifications in contingency tests of chi square test

Answer 43

Observed frequencies = real outcomes observed at conclusion of study Expected frequencies = outcomes predicted if null hypothesis was true

Question 44

What is chi-square?

Answer 44

Ratio of observed to expected frequency

Question 45

When is fisher exact test used in place of chi square?

Answer 45

If expected cell frequencies in more than 20% of cells falls less than 5

Question 46

When is Yates correction used in chi square?

Answer 46

If total sample is less than 100 of any cell value is less than 10

Question 47

When must chi square always be used?

Answer 47

Only for original frequency counts and not percentages

Question 48

What is the chi square test for paired data?

Answer 48

McNemars test

Question 49

What is the Mantel-Haenszel test?

Answer 49

A form of chi square test where the influence of binary categorical variables on one dependent variable is tested

Question 50

What is log-linear analysis?

Answer 50

Form of chi square test where log values of cell frequencies are employed

Question 51

When is log-linear analysis used?

Answer 51

When more than 2 groups or variables are studied

Question 52

Questions to ask if using statistical tests for category 2 data

Answer 52

How many dependent variables? How many independent variables? Are the variables categorical or continuous?

Question 53

Statistical tests for category 2 data

Answer 53

Testing association

Question 54

Test used if one dependent & independent variable, testing correlation in continuous, parametric data

Answer 54

Pearsons

Question 55

Test used if one dependent & independent variable testing correlation in non-parametric data

Answer 55

Spearmans Kendall's tau

Question 56

Test used if one independent & dependent variable testing regression in continuous data

Answer 56

Simple linear regression

Question 57

Test used if one independent & dependent variable testing regression using categorical data

Answer 57

Simple logistic regression

Question 58

Test used if one dependent variable and >1 independent variable testing regression in continuous data

Answer 58

Multiple linear regression ANCOA

Question 59

Test used if one dependent variable and >1 independent variable testing regression in categorical data

Answer 59

Multiple logistic regression

Question 60

Test used if 2 or more dependent variables and >1 independent variable testing regression with categorical data

Answer 60

MANOVA

Question 61

Test used if two or more dependent variable and >1 independent variable testing regression using continuous data

Answer 61

MANCOVA Multivariate multiple regression