Measurement and Sampling Flashcards

1
Q

what are variables?

A

something that varies

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2
Q

what does “constant” mean?

A

something that is fixed/does not change

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3
Q

what is a quantitative measurement?

A

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

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4
Q

what is measurement?

A

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

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5
Q

what are examples of measured things?

A

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

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6
Q

what are examples of measurement acts?

A

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

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7
Q

what are the four levels of variable measurement?

A

(NOIR) nominal, ordinal, interval, ratio

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8
Q

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

A
  • 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
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9
Q

what are nominal variables with only two levels called?

A

dichotomous or binary nominal variable

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10
Q

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

A

True

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11
Q

What are the characteristics of ordinal variables?

A
  • 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
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12
Q

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)

A

True

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13
Q

what are characteristics of interval variables?

A
  • measured along a scale
  • each position is equidistant from other scale points
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14
Q

how is an interval level of measurement achieved?

A
  • if the categories of a variable can be ranked-order
  • if the measurements for all the cases are expressed in the same units
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15
Q

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

A

True

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16
Q

what is a ratio variable?

A

interval variables with a natural zero point

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17
Q

what does natural zero point mean?

A

the zero means “none of something”

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18
Q

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

A

True

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19
Q

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

A

True

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20
Q

T or F: Ordinal attributes can be ordered

A

True

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21
Q

T or F: interval distances are meaningful

A

True

22
Q

T or F: ratio variables contain an absolute zero

A

True

23
Q

What is a measurement error?

A

when the data we collected does not represent reality

24
Q

T or F: measurement error isn’t always present

A

False: measurement error is always present to some degree

25
Q

What are random measurement errors?

A

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

26
Q

What are systematic measurement errors?

A

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

27
Q

What is reliability?

A

the consistency in our measurement

28
Q

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

A

True

29
Q

What is validity?

A

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

30
Q

How is reliability different from validity?

A

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

31
Q

How is validity different from reliability?

A

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

32
Q

what is a population?

A

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

33
Q

what is a sample?

A

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

34
Q

Why do we sample?

A

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

35
Q

What are the different types of sampling approaches?

A

probability samples and non-probability samples

36
Q

what are probability samples?

A
  • 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
37
Q

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

A

False

38
Q

What are non-probability samples?

A

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

39
Q

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

A

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

40
Q

what is inference?

A

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

41
Q

what are the different types of probability sampling?

A

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

42
Q

what is simple random sampling?

A

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

43
Q

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

A

True

44
Q

What is stratified random sampling?

A

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

45
Q

what is disproportionate random sampling?

A

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

46
Q

what is convenience sampling?

A

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

47
Q

what is snowball sampling?

A

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

48
Q

what is purposive sampling?

A

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

49
Q

what is quota sampling?

A

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

50
Q

Are convenience samples okay?

A

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

51
Q

T or F: Convenience samples are created equally

A

False: they are not ALL created equally