Measurement and Sampling

Question 1

what are variables?

Answer 1

something that varies

Question 2

what does “constant” mean?

Answer 2

something that is fixed/does not change

Question 3

what is a quantitative measurement?

Answer 3

the use of number to describe a property of an object or event

Question 4

what is measurement?

Answer 4

the use of number to describe something that happens (or doesn’t happen) in the world

Question 5

what are examples of measured things?

Answer 5

lecture attendance
temperature
clicks on a website
product units sold
brand reputation perceptions

Question 6

what are examples of measurement acts?

Answer 6

taking a baby’s temp.
asking question on a survey
counting the number of likes on a tweet

Question 7

what are the four levels of variable measurement?

Answer 7

(NOIR) nominal, ordinal, interval, ratio

Question 8

what are the characteristics for nominal (or “categorical”) variables?

Answer 8

• numbers serve as tags or labels
• numbers are not placed on a meaningful scale
• higher/lower number doesn’t mean anything
• membership is both all inclusive and mutually exclusive

Question 9

what are nominal variables with only two levels called?

Answer 9

dichotomous or binary nominal variable

Question 10

T or F: This is an example of a nominal variable
Biological sex [1=male, 0=female]

Answer 10

True

Question 11

What are the characteristics of ordinal variables?

Answer 11

• possible values are meaningfully ordered
• variables do not establish the numeric difference between data points
• indicate that only one data point is ranked higher or lower than another
• distance between number is not set or consistent

Question 12

T or F: this is an example of ordinal variables
rate teacher effectiveness as excellent (5), good (4), average (3), poor (2) or unsatisfactory (1)

Answer 12

True

Question 13

what are characteristics of interval variables?

Answer 13

• measured along a scale
• each position is equidistant from other scale points

Question 14

how is an interval level of measurement achieved?

Answer 14

• if the categories of a variable can be ranked-order
• if the measurements for all the cases are expressed in the same units

Question 15

T or F: This is an example of interval variables
GPA Scores: a 3.0 is exactly 0.5 GPA points below a 3.5

Answer 15

True

Question 16

what is a ratio variable?

Answer 16

interval variables with a natural zero point

Question 17

what does natural zero point mean?

Answer 17

the zero means “none of something”

Question 18

T or F: this is an example of an interval variable
Distance: two things can be zero inches apart

Answer 18

True

Question 19

True or False: Nominal attributes are only named, and are the weakest variable

Answer 19

True

Question 20

T or F: Ordinal attributes can be ordered

Answer 20

True

Question 21

T or F: interval distances are meaningful

Answer 21

True

Question 22

T or F: ratio variables contain an absolute zero

Answer 22

True

Question 23

What is a measurement error?

Answer 23

when the data we collected does not represent reality

Question 24

T or F: measurement error isn’t always present

Answer 24

False: measurement error is always present to some degree

Question 25

What are random measurement errors?

Answer 25

measurement errors that are small, non-systematic, and do not threaten the overall validity of data

Question 26

What are systematic measurement errors?

Answer 26

an error in measurement in which the tool does not accurately measure the concept and is perceived incorrectly by most or all of the participants

Question 27

What is reliability?

Answer 27

the consistency in our measurement

Question 28

T or F: reliability refers to the level of clarity in the tool

Answer 28

True

Question 29

What is validity?

Answer 29

the ability or potential of a data collection tool to capture and measure the construct or the phenomenon that we are interested in measuring

Question 30

How is reliability different from validity?

Answer 30

reliability pertains to a measurement approach's ability to yield consistent results

Question 31

How is validity different from reliability?

Answer 31

validity refers to a measurement approach's ability to measure what is supposed to happen

Question 32

what is a population?

Answer 32

the entire group of people that are the focus of the study

Question 33

what is a sample?

Answer 33

a subset of the population, ideally representative of all the characteristics of the population

Question 34

Why do we sample?

Answer 34

it's often impossible or counterproductive to collect data from all members of population

Question 35

What are the different types of sampling approaches?

Answer 35

probability samples and non-probability samples

Question 36

what are probability samples?

Answer 36

- every element of the population has a known chance of being selected for inclusion - every element has a non-zero chance of being included in the sample

Question 37

T or F: probability samples provide every element of the population with an equal change for inclusion

Answer 37

False

Question 38

What are non-probability samples?

Answer 38

not all elements of a population have an opportunity to be included in the sample

Question 39

T or F: probability samples do not allow us to make inferences about a population

Answer 39

False: non-probability samples do not allow us to make inferences about a population

Question 40

what is inference?

Answer 40

a conclusion or opinion that is formed because of known facts or evidence

Question 41

what are the different types of probability sampling?

Answer 41

1) simple random sampling 2) stratified random sampling 3) disproportionate random sampling 4) convenience sampling 5) snowball sampling 6) purposive sampling 7) quota sampling

Question 42

what is simple random sampling?

Answer 42

all members of a population have an equal change of being selected for the sample

Question 43

T or F: In simple random sampling, members of a population are selected at random for inclusion in the sample

Answer 43

True

Question 44

What is stratified random sampling?

Answer 44

a population is divided into subgroups or strata, then a random sample is subsequently drawn from each strata

Question 45

what is disproportionate random sampling?

Answer 45

similar to proportional random sample except that sample proportions are not equivalent to population proportions

Question 46

what is convenience sampling?

Answer 46

sample is drawn from those that are available or easy to collect data from

Question 47

what is snowball sampling?

Answer 47

generates a convenience sample of respondents then asks them to recommend others who might be interested in providing data

Question 48

what is purposive sampling?

Answer 48

when researches purposefully select from a group of people of theoretical interest - experts, extreme cases, typical cases

Question 49

what is quota sampling?

Answer 49

generation of a sample that has attributes proportional to a given population

Question 50

Are convenience samples okay?

Answer 50

Yes and No: they restrict the ability to make population-level inferences BUT are time and cost efficient

Question 51

T or F: Convenience samples are created equally

Answer 51

False: they are not ALL created equally