Descriptive statistics

Question 1

Cognitive biases

Answer 1

Ways of thinking that predispose one to favour a certain viewpoint over others

Question 2

Confirmation bias

Answer 2

Tendency to search for or interpret information in a way that confirms one’s preconceptions while ignoring information that doesn’t support them

Question 3

Selection bias

Answer 3

Distortion of evidence or data that arises from the way that the data is collected or the way that samples are selected to study

Question 4

Supervisorship bias

Answer 4

Ignores the unsuccessful outcomes of a selection process

Question 5

Publication bias

Answer 5

Scientific journal editors and publishers more likely to publish studies with positive results over those with negative results

Question 6

Descriptive statistics

Answer 6

Communicate results without generalising beyond the sample to a larger group

Question 7

What are the 4 levels of measurements

Answer 7

1. Nominal
2. Ordinal
3. Interval
4. Ratio

Question 8

Nominal scale

Answer 8

Variables which have no numerical value and are in categories

Question 9

Ordinal scale

Answer 9

Rank order categories from highest to lowest

Question 10

Interval scale

Answer 10

When dealing with an interval scale, the difference between any 2 values can be calculated by using subtraction

Question 11

Ratio scale

Answer 11

Quantitative data with true 0, Can add, subtract, multiply and divide

Question 12

Why is distribution important (3)

Answer 12

• Determines which measure of central tendency to use
• Determines which measure if variability to use
• Determines further statistical analysis

Question 13

Normal distribution

Answer 13

Even bell shaped curve

Question 14

Non-normal distribution

Answer 14

Either…
- Negative skew (R)
- Positive skew (L)

Question 15

Objective assessment of normality

Answer 15

Most variables follow a distribution that is not entirely normal

Question 16

What are the 3 measures of central tendency

Answer 16

1. Mode
2. Median
3. Mean

Question 17

Mode

Answer 17

Most frequently occuring score/value

Question 18

Median

Answer 18

Middle score when all values are in numerical order before calculating the median

Question 19

Mean

Answer 19

Arithmetic average. Add up all values and divide by the number of values collected

Question 20

What measure of central tendency is used when data is normally distributed

Answer 20

Mean

Question 21

What measure of central tendency is used when data is non-normally distributed

Answer 21

Median

Question 22

What are the 3 measures of spread/range

Answer 22

1. Range
2. Interquartile range
3. Standard deviation

Question 23

Range

Answer 23

Largest value - Smallest value

Question 24

Standard deviation

Answer 24

Measures the average amount by which all the values deviate from the mean

Question 25

Interquartile range

Answer 25

Upper quartile – Lower quartile 

Question 26

Variance

Answer 26

Is a measure of how scattered around the average value (expected value) one finds the measured values of a variable

Question 27

Small variance

Answer 27

Means that measured values are on average, closer to the mean of the sample

Question 28

Large variance

Answer 28

Means that measured values vary widely from the mean

Question 29

What measure of spread/variance is used when data is normally distributed

Answer 29

Standard Deviation

Question 30

What measure of spread/variance is used when data is non-normally distributed

Answer 30

Interquartile range (IQR)

Question 31

Error bars

Answer 31

Values are reported as the measure of central tendency (normal mean or median) +/- the measure of variance (standard deviation or interquartile range)