Chapter One: Collecting Data

Question 1

categorical variable

Answer 1

variables whose data represent a categories (ie: gender, type of car, etc.)

Question 2

cluster

Answer 2

naturally occurring groups (countries)

Question 3

cluster sample

Answer 3

divide N items in the frame into clusters that contain several items within

Question 4

continuous variable

Answer 4

under numerical category - data represents timing measurements

Question 5

convenience sample

Answer 5

type of non-probability sample, items that are easy, inexpensive, and convenient

Question 6

coverage error

Answer 6

type of error in a survey that can lead to ethical concerns of selection bias, when certain groups are excluded from the frame

Question 7

data cleaning

Answer 7

corrects inconsistent data errors that could effect statistical results

Question 8

discrete variable

Answer 8

type of numerical variable - includes variables that represent a “number of something”

Question 9

frame

Answer 9

a complete or partial listing of the items that make up the population from which the sample will be selected

Question 10

interval scale

Answer 10

expresses a difference between measurements that do not include a true zero point

Question 11

judgment sample

Answer 11

opinions of preselected experts in the subject matter

Question 12

measurement error

Answer 12

type of survey error

Question 13

measurement scale

Answer 13

defines the ordering of values and determines if differences among pairs of values for a variable are equivalent

Question 14

nominal scale

Answer 14

category values express no order or ranking

Question 15

non-probability sample

Answer 15

items or individuals selected without knowing their probability of being selected (used to obtain informal approximations)

Question 16

nonresponse error

Answer 16

type of survey error that arises from failure to collect data on all items in the sample

Question 17

numerical variable

Answer 17

variables whose data represent a counted or measured quantity

Question 18

operational definition

Answer 18

specifies the type of variable and scale (type of measurement) that the variable uses

Question 19

ordinal scale

Answer 19

an ordering or ranking of category values is implied

Question 20

outlier

Answer 20

values that seem excessively different from most other values

Question 21

population

Answer 21

contains all the items or individuals of interest that one seeks to study

Question 22

probability sample

Answer 22

items selected based on known probabilities

Question 23

ratio scale

Answer 23

an ordered scale that includes a true zero point

Question 24

recoded variable

Answer 24

supplements or replaces the original variable in the analysis

Question 25

sample

Answer 25

contains only a portion of a population of interest

Question 26

sampling error

Answer 26

type of survey error that occurs when there is variation from sample to sample

Question 27

sampling with replacement

Answer 27

selected items are returned to the frame and have the same probability of being selected again

Question 28

sampling without replacement

Answer 28

selected items are not returned to the frame and can never be selected again

Question 29

simple random sample

Answer 29

method of sampling - every item from a frame has the same chance of selection 1/N

Question 30

stacked

Answer 30

pair the single numerical with the categorical

Question 31

strata

Answer 31

subpopulations w/ some common characteristic

Question 32

stratified sample

Answer 32

divide the N items int he frame into separate subpopulations (strata) then select simple random within, and combine the results

Question 33

systematic sample

Answer 33

partition the N items in the frame into n groups of K items (k=N/n)

Question 34

table of random numbers

Answer 34

method of selecting at random (opposite of fishbowl) consists of a series of digits listed in a randomly generated sequence

Question 35

treatment

Answer 35

the effect of some change on a variable of interest

Question 36

unstacked

Answer 36

create separate numerical variables for each group