Choosing Statistical Test 2

Question 1

What is one sample t test used for?

Answer 1

To compare mean of single sample with known population mean to check if sample is derived from the population

Question 2

What does one sample t test need?

Answer 2

Observed sample mean

Hypothesised derived population mean

Question 3

What is needed for one sample t test?

Answer 3

Variable must be normally distributed

Sample size must be adequate to prevent extreme skewness

Question 4

What is two sample t test also known as?

Answer 4

Students t

Question 5

What is two sample t test used for?

Answer 5

To compare means of two samples

Question 6

What does two sample t test need?

Answer 6

Two variables - one independent variable which can be nominal and a dependent variable which is quantitative

Question 7

What does unpaired t test compare?

Answer 7

Independent samples where observation is made only once in each individual in a sample

Question 8

What is compared in a paired t test?

Answer 8

Sample means are compared in same group

Here each subject is observed twice and scores are compared for statistical significance

Question 9

What does t test assume?

Answer 9

Equal variance among two groups

Question 10

What can be used to test variance between two groups?

Answer 10

Levenes test

Question 11

What is ANOVA used for?

Answer 11

To compare means of multiple groups

Question 12

What is ANOVA based on?

Answer 12

Variance comparisons

Question 13

What is one-way ANOVA?

Answer 13

If one independent variable is compared across more than 2 groups

Question 14

What happens in 2 way ANOVA?

Answer 14

2 independent variables are analyzed in multiple groups

Question 15

When is repeated measures ANOVA used?

Answer 15

When same measures are used on multiple occassions

Question 16

How is ANOVA calculated?

Answer 16

Using ratio of variation between groups to variation within groups

Question 17

What is the name of the type of calculation used in ANOVA?

Answer 17

F statistics

Question 18

Disadvantages of ANOVA

Answer 18

It can only tell us if a significant difference exists among groups; it does not tell us where the difference comes from

Question 19

Why are post hoc significance tests used after ANOVA?

Answer 19

ANOVA cannot tell us where the difference came from

Question 20

Assumptions made if ANOVA is used

Answer 20

Normal distribution of observations in groups
Equal variance among tested groups
Independent observations - not paired except for repeated measures test

Question 21

Recommended test if >2 groups, 1 independent variable and testing between subjects

Answer 21

One way ANOVA

Question 22

Recommended test if >2 groups, 1 independent variable and testing within subjects

Answer 22

Repeated measure ANOVA

Question 23

Recommended test if >2 groups, >1 independent variable testing between subjects

Answer 23

Factorial ANOVA

Question 24

Recommended test if >2 groups, >1 independent variable and testing within subjects

Answer 24

MANOVA

Question 25

What is degrees of freedom (df)?

Answer 25

When we calculate an estimate of one statistic from an estimate of another

Question 26

What happens to degree of freedom if applied to regression or ANOVA?

Answer 26

We lose one degree of freedom for each parameter estimate carried out before estimating the standard deviation

Question 27

Degree of freedom for chi square if rows and columns marginal totals are specified

Answer 27

1

Question 28

Degree of freedom if chi square distribution where proportions are estimated

Answer 28

(number of rows - 1) x (number of columns - 1)

Question 29

What is the degree of freedom in a t test?

Answer 29

Sum of the persons in both groups minus 2

Question 30

Degree of freedom in sample mean

Answer 30

n (sample size)

Question 31

Df in population SD estimated from sample

Answer 31

n-1

Question 32

Df in two sample t test

Answer 32

(n1 + n2) - 2

Question 33

Df in chi square

Answer 33

(Rows - 1) x (columns - 1)

Question 34

Df in one sample t

Answer 34

N - 1

Question 35

Df in one way ANOVA: total variance

Answer 35

Total N - 1

Question 36

Df in one way ANOVA within groups

Answer 36

Total N - number of groups

Question 37

Df in one way ANOVA between groups

Answer 37

Number of groups - 1