Descriptive Statistics

Question 1

Characteristics that may differ (vary) among individuals

Answer 1

Variables

Question 2

values of variables for individuals (singular datum)

Answer 2

data

Question 3

an individual; symbolize: x1, X2, …Xn (n=sample size)

Answer 3

case/ovservation

Question 4

all individuals of a specified part of the universe (cf biological definition)

Answer 4

population

Question 5

subset of population; used to make inferences regarding the population (usually unknown)

Answer 5

sample

Question 6

physical measurement error, and a difference between the real population value and the estimates (from sample data) of the population value.

Answer 6

error

Question 7

all the individuals have equal probability of being sampled

Answer 7

randomness

Question 8

value of one case does not affect the value of other cases (exception e.g., repeated measures on same individual - dependence by design)

Answer 8

independence

Question 9

values not quantitative or ranked; no mathematical or value relationship, mutually exclusive categories (e.g. male/female); 1 variable type: categorical

Answer 9

categorical scale (nominal)

Question 10

relative differences( eg greater than/less than); no mathematical relationships between values (eg, small/medium/large; highly active/not active; health status: 1=healthy, 2=ill, 3=sick, 4=hospitalized, 5= dead, 1 variable type: ranked

Answer 10

Ranked scale or Ordinal

Question 11

mathematically defined distance btween values; quantitative, absolute zero point; 2 variable type, may convert ration data to ranked/categorical data (not visa versa)

Answer 11

Ratio scale

Question 12

may assume only certain values within given range(eg, 1,2,3,4)

Answer 12

discrete

Question 13

may assume any value within given range (1.0,2.0,2.34,2.344, ect)

Answer 13

continuous

Question 14

mathematically defined distance between values; quantitative; arbitrary zero point, (eg Celsius temperature scale), 2 variable types, may convert interval data to ranked/categorical data(not vice versa)

Answer 14

Interval scale