Analysing Quantitative Data

Question 1

What are the 2 ways to analyse quantitative data?

Answer 1

Measures of central tendency - mean, median and mode
Measures of dispersion - range, standard deviation

Question 2

When theres an anomaly, what statistic test do you use?

Answer 2

Median and standard deviation

Question 3

Describe what is meant be measures of central tendency?

Answer 3

General term for any measure of the average value in a set of data e.g. mean

Question 4

What are the 3 measures of central tendency?
And what level of measurement are they used with?

Answer 4

Mode = most common numbers, used with nominal data
Median = middle value in a ranked list, used with ordinal data
Mean = add all scores up, divide by number of values present, used with interval data

Question 5

What is a strength of the mode?

Answer 5

• easy to calculate + less prone to distortion by anomalies
• as it does not take all data into account

UNLIKE the mean which is highly influenced by anomalies as it takes all data into acc

Question 6

What is a weakness of the mode?

Answer 6

• less accurate
• doesnt take account of all scores
• mode may also not be useful if theres more than 1 mode

UNLIKE the mean which takes all data into acc

Question 7

What is a strength of the median?

Answer 7

• easy to calculate + not affected by anomalies
• as it doesnt take all scores into acc

UNLIKE mean which takes all data into acc so highly influenced by anomalies

Question 8

What is a weakness of the median?

Answer 8

• not as valid as mean
• as it doesnt take all scores into acc
• less useful results

Question 9

What is a strength of the mean?

Answer 9

• most accurate + valid
• uses all data sets

UNLIKE median which doesn’t take acc of all data

Question 10

What is a weakness of the mean?

Answer 10

• highly affected by anomalies
• as it takes all scores into acc
• can result in misleading interpretation of results

Question 11

What is meant by measures of dispersion?

Answer 11

• based on the spread of scores
• how far the score varies from the mean
• e.g. range or SD

Question 12

What are the 2 types of measures of dispersion?
What levels of measurements are they used for?

Answer 12

Range - spread of data from smallest to largest, take lowest value from highest, used for ordinal data

Standard deviation - measure of spread around the mean, higher the sd, the more the data is spread around the mean, used for interval data

Question 13

What is a strength of the range?

Answer 13

• easy + quick to calculate
• as it only uses 2 pieces of the data to calculate

UNLIKE the standard deviation which is more complicated + time consuming to calculate

Question 14

What is a weakness of the range?

Answer 14

• can be distorted by anomalies
• as it only takes into account highest + lowest values
• so an inaccurate range could be achieved

Question 15

Describe what standard deviation is

Answer 15

• measure of spread around the mean
• the higher the SD, the more data is spread around mean, less consistency + more indv differences
• the lower the SD, the data is clustered around mean, more consistency, less indv differences
• used for interval data

Question 16

What are the strengths of standard deviation?

Answer 16

• more precise + valid
• uses all scores so more accurate
• than range which only looks at smallest and largest data
• less easily distorted by anomalies
• takes into acc all scores
• not just highest and lowest data like range

Question 17

What is a weakness of standard deviation?

Answer 17

• more complicated + time consuming to calculate
• unlike range which is quick and easy