measures of dispersion

Question 1

measures of dispersion

Answer 1

any measure of the spread of variation in a set of scores

Question 2

range

Answer 2

a calculation worked out by taking the lowest value away from the highest value, and usually adding one

Question 3

standard deviation

Answer 3

describes how much scores deviate from the mean, by calculating the difference between the mean and each score, adding all these differences up and dividing by the number of scores- gives the variance
SD is the square root of the variance

Question 4

large standard deviation

Answer 4

the larger the standard deviation, the greater the dispersion within a set of data.
particular condition- not all participants were affected by the IV in the same way as data quite widely spread. may be a few anomalous results.

Question 5

low standard deviation

Answer 5

data tightly clustered around the mean. may imply that all participants responded in a fairly similar way.

Question 6

range- strengths

Answer 6

easy to calculate

Question 7

range- weaknesses

Answer 7

may be unrepresentative of data set as whole. only takes into account two most extreme values.

Question 8

standard deviation- strengths

Answer 8

much more precise measure of dispersion than range. includes all values within final calculation.

Question 9

standard deviation- weaknesses

Answer 9

can be distorted by a single extreme value.