Quantitative data analysis and distributions

Question 1

What is quantitative data?

Answer 1

Results that can be counted, usually given as numbers

Question 2

What is qualitative data?

Answer 2

Results that are expressed as non-numerical. they may take the form of a written description of the thoughts, feeling and opinions of participants.

Question 3

What are the 3 levels of measurement (quantitative data)

Answer 3

Nominal - Categories
Ordinal - Numerical scale, non-standardised (subjective)
Interval - Standardised scale (e.g. time)

Question 4

What are descriptive statistics

Answer 4

A way of using numbers to describe the data that you have

Question 5

Examples of descriptive statistics

Answer 5

Measures of central tendency (mean, median, mode)
Measures of dispersion (range, standard deviation)
Graphs

Question 6

What measure of central tendency and dispersion is used for each level of measurement

Answer 6

Nominal - mode
Ordinal - median range
Interval - mean, S.D.

Question 7

Strengths of central tendencies

Answer 7

Median - Not affected by extreme scores so is useful under such circumstances, appropriate for ordinal data and is easier to calculate than the mean
Mean - most sensitive, takes into account all values, representative of the data as a whole
Mode - only measure than can be used for nominal data

Question 8

Strengths of measures of dispersion

Answer 8

Range - easy to calculate
S.D. - precise measure as takes all values into account so more representative

Question 9

Weaknesses of measures of central tendency

Answer 9

Median - not sensitive, exact values are not reflected in the middle value
Mean - can be distorted by one extreme value so may be misrepresentative
Mode - can be very different from other measures so not representative

Question 10

Weaknesses of measures of dispersion

Answer 10

Range - affected by extreme values as only takes into account two values so misrepresentative
S.D. - affected by one extreme value as only takes into account two values so misrepresentative

Question 11

What are scattergrams used for?

Answer 11

Correlations

Question 12

What are bar charts used for?

Answer 12

Usually nominal data (non continuous), there are gaps

Question 13

What are histograms used for?

Answer 13

Continuous data (usually interval or ordinal)

Question 13

What does a positively skewed distribution look like?

Answer 13

Ghost facing home (mode, median, mean)

Question 14

What does a negatively skewed distribution look like?

Answer 14

Ghost facing away from home (mean, median, mode)