RM L9: Measures of spread -

Question 1

What is measure of centeral tendency?

Lesson 9

Answer 1

• sometimes called a measure of average
• represents how data clusters around a centeral point in data set
• ## supposed to represent a typical score from collected data

Question 2

What is measure of spread?

Lesson 9

Answer 2

• Measure of dispersion
• Gives an index of how spread the data is around a measure of centeral tendency

Question 3

What is range?

Lesson 9

Answer 3

• Shows how widely data is spread between lowest + highest scores
• Larger the range the wider the data is spread
• Find highest and lowest values then subtract

Question 4

What are the 3 strengths of range?

Lesson 9

Answer 4

1. Quick and easy to calculate
2. Can draw conclusions quickly
3. Less time calculating more time spent on analysis results

Question 5

What are the 2 weaknesses of range?

Lesson 9

Answer 5

1. Vulnerable to extreme scores
2. Range is not always representative of set of data

Question 6

What is stantard deviation (SD)?

Lesson 9

Answer 6

• Gives precise information about spread around the mean
• Smaller SD suggests suggests data scores are clustered more tightly around the mean
• Larger SD suggests that data points more diverse mean is not representative
  1. Mean is subtracted from each data point to see how far each score deviates from the mean –> researcher can identify average amount of deprivation from mean

Question 7

What are the 2 strengths of SD?

Lesson 9

Answer 7

1. Most precise measure of dispersion
2. Considers all scores unlike ranges –> very representative

Question 8

What are the 3 weaknesses of SD?

Lesson 9

Answer 8

1. Requires mean to be measure of C.T
2. Only used with interval data not ordinal, nominal
3. Does not cover all data types (limited with regards to its use)

Question 9

What does low stantard deviation score mean?

Lesson 9

Answer 9

• Less varying scores
• Mean (measure of centeral tendency) good representation of data set
• Data in set is similar

Question 10

What does high stantard deviation score mean?

Lesson 9

Answer 10

• More varying scores
• Mean (measure of centeral tendency) not good representation of data
• Data is different

Question 11

Give the examples of SD + CT

Lesson 9

Answer 11

SD > range
CT > mean, mode, median