eModule 2

Question 1

What are the three types of data?

Answer 1

1. Quantitative
2. Categorical
3. Qualitative

Question 2

What are the two types of categorical data?

Answer 2

Nominal (named) and Ordinal (ranked)

Question 3

What are the two types of quantitative data?

Answer 3

Continuous and discrete

Question 4

Define normality

Answer 4

A measure of central tendency. 2/3rd of the data is 1s.d. above ad below the mean and 50% of the data is above the mean and 50% below

Question 5

Describe Gaussian distribution

Answer 5

Symmetric, central distribution with well-behaved tails. mean=median=mode

Question 6

Describe skewness

Answer 6

asymmetrical distribution in which there are many data points at the high/ low end. Long, uneven tails

Question 7

Describe Kurtosis

Answer 7

Data with heavy or light tails tails relative to those in a normal distribution

Question 8

Normality can be assessed visually using which two graphs?

Answer 8

Histograms and Box and Whisker plots

Question 9

Which stats tests can you use to assess normality? and when would you use them?

Answer 9

Shapiro-Wilks test (n<50)

Kolmogorov-Smirnov test (n>50)

Question 10

Name three measures of central tendency

Answer 10

1. Mean
2. Median
3. Mode

Question 11

Name five measures of dispersion of data

Answer 11

1. Standard deviation
2. Variance
3. Range
4. SEM
5. Confidence intervals

Question 12

How is SEM calculated and what does it describe?

Answer 12

SD/ square root of n

Measures how well a sample mean approximates a population mean

Question 13

How are Confidence intervals calculated and what does it describe?

Answer 13

SEM x 1.96

The range in which the true mean value might be found

Question 14

When is data dependent (paired)?

Answer 14

Longitudinal experiments

When the same variables are measured in the same subjects at different time points.

Question 15

When is data independent (unpaired)?

Answer 15

cross-sectional studies

When two groups are being compared with no common factors.

Question 16

What two components are obtained from a person’s correlation and what do they indicate?

Answer 16

• an r-value: person’s correlation coefficient indicates strength of correlation
• a p- value: indicates the probability that the observed relation was due to chance

Question 17

What are the two components of the Spearman’s correlation (used when data is not normally distributed)?

Answer 17

Spearman’s rho

p-value

Question 18

Define correlation

Answer 18

indicates the strength of the relationship between two variables

Question 19

Define regression

Answer 19

Quantifies the association between two variables. It tells us the impact that changing one variable will have on another variable. It is defined by y=a +bx

Question 20

Why are parametric stats used over non-parametric? (3)

Answer 20

· Easier to understand
· Analyses are more powerful
· Less likely to incorrectly reject/fail to reject the hypothesis

Question 21

When data is parametric which measure of central tendency is used?

Answer 21

Mean

Question 22

When data is non-parametric which measure of central tendency is used?

Answer 22

Median

Question 23

Rank the 7 different types of evidence from strongest to weakest

Answer 23

1. Systematic reviews and meta-analyses
2. Randomised control trials
3. Well designed control trials
4. Case control studies
5. Systematic reviews of descriptive studies
6. Descriptive cross-sectional studies
7. Case report/series