research methods- measures of central tendency and dispersion

Question 1

what’s the mean?

Answer 1

add up all the scores and divide by the number of scores

Question 2

evaluation of the mean

Answer 2

-sensitive measure
-may be unrepresentative

Question 3

ao3 of mean: sensitive measure

Answer 3

-includes all the scores/values in the data set within the calculation
-represents the data better than the median or the mode

Question 4

ao3 of mean: may be unrepresentative

Answer 4

-one very large or very small number makes it distorted
-median or mode tend not to be so easily distorted

Question 5

what’s the median?

Answer 5

middle value, place scores in ascending order and select middle value
If there are two values in the middle, the mean of these is calculated.

Question 6

evaluation of the median

Answer 6

+less affected by extreme scores
-less sensitive than the mean

Question 7

ao3 of median: less affected by extreme scores

Answer 7

-median is only focused on the middle value
-some cases it may be more representative of the data set as a whole

Question 8

ao3 of median: less sensitive than the mean

Answer 8

-actual values of lower and higher no.s are ignored
-extreme values Amy be important

Question 9

what is the mode?

Answer 9

most frequent or common value, used with categorical/nominal data

Question 10

evaluation of the mode

Answer 10

+relevant to categorical data
-an overly simple measure

Question 11

ao3 of mode: relevant to categorical data

Answer 11

-when data is ‘discrete’ i.e. represented in categories
-sometimes the mode is the only appropriate measure

Question 12

ao3 of mode: an overly simple measure

Answer 12

-mode may be at one extreme
-it’s not a useful way of describing data when there are many modes

Question 13

what are the three measures of central tendency?

Answer 13

-mean
-median
-mode

Question 14

what is the range?

Answer 14

the difference between highest to lowest value (sometimes 1 is added if values have been rounded up or down)

Question 15

evaluation of range

Answer 15

+easy to calculate
-doesn’t account for the distribution of the scores

Question 16

ao3 of the range: easy to calculate

Answer 16

-arrange values in order and subtract largest from smallest
-simple formula, easier than the standard deviation

Question 17

ao3 of the range: doesn’t account for the distribution of the scores

Answer 17

-range doesn’t indicate whether most numbers are closely grouped around the mean or spread out evenly
-standard deviation is much bettie measure of dispersion in this respect

Question 18

what is standard deviation?

Answer 18

measure of the average spread around the mean. The larger the standard deviation, the more spread out the data is

Question 19

evaluation of standard deviation

Answer 19

+more precise than the range
-may be misleading

Question 20

ao3 of standard deviation: more precise than the range

Answer 20

-includes all values within the calculation
-therefore more accurate picture of the overall distribution of data set

Question 21

ao3 of standard deviation: it may be misleading

Answer 21

-can be distorted by extreme values
-also, extreme values may not be revealed unlike with the range

Question 22

what are the two measures of dispersion?

Answer 22

-range
-standard deviation