KA3.2e - Presentation of Data

Question 1

What types of data do discrete and continuous variables give rise to?

Answer 1

qualitative, quantitative, or ranked data

Question 2

Define ‘qualitative data’

Answer 2

subjective and descriptive data

e.g. I feel sore

Question 3

Define ‘quantitative data’

Answer 3

measured objectively, usually with a numerical value

e.g. the absorbance is 0.672

Question 4

Define ‘ranked data’

Answer 4

data transformation in which numerical values are replaced by their rank when the data are sorted from lowest to highest.

e.g. runner’s time in race is converted to 1st, 2nd, 3rd place etc.

Question 5

What are the consequences of the type of variable being investigated?

Answer 5

the graphical display or statistical tests that may be used

Question 6

State what a box plot is used to show?

Answer 6

the spread and variation within and between data sets

e.g. between samples or replicates in your project

Question 7

What does the Inter Quartile Range (IQR) represent in a box plot?

Answer 7

spread of where the middle 50% of the data falls

Question 8

What does the median represent in a box plot?

Answer 8

The median is the line in the middle of the IQR.

Represents the middle number if all values in the dataset were listed from smallest to biggest

Question 9

What does the Third/Upper Quartile represent in a box plot?

Answer 9

The Third/Upper Quartile is the right or top edge of the box plot.

Represents the point above which 25% of the values from the dataset fall.

Question 10

What does the First/Lower Quartile represent in a box plot?

Answer 10

The First/Lower Quartile is the left or bottom edge of the box plot.

Represents the point below which 25% of the values from the dataset fall.