DESCRIPTIVE STATISTICS

Question 1

Descriptive stattistics

Answer 1

1. measures of central tendency - mean, median and mode
2. measures of dispersion - range and standar deviation

Question 2

mode

Answer 2

most frequent score in qualitative data set.
if there are two modes data is bimodal

Question 3

strenghts of using mode

Answer 3

• mode is not distorted by extreme scores called outliers
• ## mode is more helpful for discrete numbers easy to say 2 than saying 1.89

Question 4

limitations of using mode

Answer 4

• mode doesnt include all the values in the calculation
• there can be no mode if every value is different or multiple mode , mode doesnt give an exact average value.

Question 5

median

Answer 5

middle score when the data is put in order

Question 6

strenghts of using median

Answer 6

1. quick and easy to calulate
2. as median is the central value, its not affected by extremely high or low scores - can be used on skewed data sets to give a representative value.

Question 7

limitations of median

Answer 7

• median doesnot include all the values in the calculation so its not sensitive as mean.
• if there are even numbers, the typical value will be a number outside of recorded values.

Question 8

mean

Answer 8

mathematical average calulated by adding all the values and then dividing by the number of values.

Question 9

strengths of mean

Answer 9

• all the raw data is included in the mean, so mean is the most sensitive central tendency

Question 10

limitations of mean

Answer 10

• due to sensitivity of the mean, its extremely distorted by outliers.

Question 11

range

Answer 11

difference between data sets highest and lowest values.

Question 12

strengths of range

Answer 12

• easier to calculate as compared to the alternative standard deviation.

Question 13

limitations of range

Answer 13

completely ignores the central vakue so can be misleading if there are extremely high or low values.

Question 14

standard deviation

Answer 14

complex calculation which uses all the data points to produce a single value.
- small the standard deviation, less spread the values are around the mean.

Question 15

strengths of standard deviation

Answer 15

• all scores in set are taken into account so its more accurate than the range.
• provides information about spread of scores.

Question 16

limitations of standard deviation

Answer 16

• extreme scores distorts the sd
• sd is significantly more difficult to calculate than the range.

Question 17

advantages of correlational study

Answer 17

• doesnt involve controlling any variables so it can be done when a controlled experiment isnot done
• can be used to test for reliability and validity
  good reliable test will show a high correlation