Descriptive Stats

Question 1

what is a univariate stat?

Answer 1

observed distribution of cases for a single variable at a time; illustrate # of times values of a variable are observed in a sample

Question 2

what is the calculation for percentage in a grouped frequency table?

Answer 2

(responses) / (total responses)

Question 3

what is the calculation for a valid percentage in a grouped frequency table?

Answer 3

(responses)/(total responses - invalid responses)

Question 4

what is the calculation for a cumulative percentage in a grouped frequency table?

Answer 4

add valid percentages as you go down the table

Question 5

who is Florence Nightingale?

Answer 5

mother of descriptive stats and inventor of pie charts

Question 6

which variables are best for bar charts?

Answer 6

nominal/ordinal (discrete)

Question 7

which variables are best for pie charts?

Answer 7

discrete variables

Question 8

which variables are best for histograms?

Answer 8

discrete variables that are technically continuous

Question 9

which variables are best for line charts?

Answer 9

continuous variables

Question 10

what are 3 ways people lie in stats using graphs/charts?

Answer 10

1. low density charts
2. make aesthetics top priority
3. poorly organized categories

Question 11

what are the qualities of nominal measurements?

Answer 11

qualitative, can’t be ranked, mutually exclusive, used as categories

Question 12

what are the qualities of ordinal measurements?

Answer 12

can be either qualitative/quantitative, can be ranked/ordered, distance between data points isn’t meaningful

Question 13

what are the qualities of interval measurements?

Answer 13

qualitative, distance between data points is meaningful, no “true” zero, can (+)/(-) values

Question 14

what are the qualities of ratio measurements?

Answer 14

qualitative, distance between data points is meaningful, “true” zero, can (+)/(-) and (x)/(divide) values

Question 15

what are central tendencies?

Answer 15

avg. or typical values of a distribution

Question 16

what is a mean and which variables is it best for?

Answer 16

an average value, best for interval and ratio variables

Question 17

what are pros and cons of means?

Answer 17

pro = simplifies presentation of data
con = vulnerable to outliers

Question 18

what is a median and which variables is it best for?

Answer 18

value of middle cases, good for all variables except nominal but best for ordinal

Question 19

what are pros and cons of medians?

Answer 19

pro = not affected by outliers
con = doesn’t take into account value of all cases in a distribution

Question 20

what is a mode and which variables is it best for?

Answer 20

most frequent variable, can be used for all variables but best for interval and ratio

Question 21

what is dispersion?

Answer 21

ways values are distributed around some central value (usually the mean)

Question 22

what is a range and which measures is it used for ?

Answer 22

distance between the highest and lowest value, used in ordinal levels and up

Question 23

what are the pros and cons of range?

Answer 23

pro = get initial sense of dispersion
cons = vulnerable to outliers and less statistically sophisticated

Question 24

what is a variance / standard deviation and which measures is it used for?

Answer 24

avg. amount of deviation from mean value, used for interval and ratio measures