The Measurement

Question 1

Descriptive Statistics is what?

Answer 1

Concerned with the presentation, organization, and summarization of sample data

Question 2

Inferential Statistics is what?

Answer 2

Allows us to generalize or make inferences from our sample of data to a larger group of subjects (population)

Question 3

What is the population?

Answer 3

The largest collection of persons for which we have an interest at a particular time

Question 4

What are inferential statistics used to analyze?

Answer 4

Used to make an educated guess about the population parameter

Question 5

What are descriptive statistics used to calculate what?

Answer 5

Mean from the sample data

Question 6

What is the Statistic Number?

Answer 6

The number we get from the people (study) we have that we use to estimate the parameter we will have

Question 7

What is the variable?

Answer 7

What is being observed or measured

Question 8

What is the constant?

Answer 8

A measurement that stays the same from observation to observation

Question 9

What are the two categories under Quantitative?

Answer 9

Continuous or Discrete

Question 10

What are the types of variables under continuous?

Answer 10

Interval and Ratio

Question 11

What are the types of variables under discrete?

Answer 11

Ratio

Question 12

What is an interval variable?

Answer 12

Equal distance; arbitrary zero (neg value has meaning)

Question 13

What is a continuous ratio variable?

Answer 13

Equal distance; meaningful zero (neg value has NO meaning)

Question 14

What is discrete ratio variable?

Answer 14

Equal distance; variable only exists in whole numbers, meaningful zero

Question 15

Discrete Variable

Answer 15

Categorical Variable; variable that can have one one of a limited set of values or only whole numbers

Question 16

What is a Nominal Scale

Answer 16

Categorical; no implied order among the categories

Question 17

What does dichotomous mean?

Answer 17

2 categories

Question 18

Can a nominal scale have more than 2 categories?

Answer 18

Yes

Question 19

What is an Ordinal Scale?

Answer 19

Consist of ordered categories, where the differences between categories cannot be considered equal

Question 20

What is a Continuous Variable?

Answer 20

Numeric variable; that may take an infinite number of values within a given range

Question 21

Does a continuous variable posses gaps/interruptions like a discrete variable?

Answer 21

No, continuous variables do NOT need to be whole numbers

Question 22

What is an Interval Scale?

Answer 22

Continuous; equal distance between values, but the zero point is arbitrary

Question 23

What is an example of the interval scale?

Answer 23

Temperature, size 0 degrees does not mean nothing

Question 24

What is a Ratio Scale?

Answer 24

Continuous; has equal intervals between values and a meaningful zero point, which represents absence of the characteristic being measured

Question 25

What variable can fit as a ratio scale?

Answer 25

Discrete variable when the variable exists ONLY in whole numbers

Question 26

What does NOIR mean?

Answer 26

Nominal: named categories Ordinal: same as nominal + ordered categories Interval: same as ordinal + equal intervals Ratio: same as interval + meaningful zero

Question 27

What is the independent variable?

Answer 27

The intervention, or what is being manipulated

Question 28

What is the dependent variable?

Answer 28

The outcome of interest that should change in response to some intervention

Question 29

Ex. New medication that treats pain and one of the suspected side effects is nausea, if the patient rates nausea on a scale from 1-10 what is the level of measurement?

Answer 29

Ordinal, there is an order

Question 30

What is the Central Tendency?

Answer 30

A single value that is considered 'typical' of the set of data as a whole

Question 31

What are the 3 most commonly used measures?

Answer 31

Arithmetic Mean IR Median OIR Mode NOIR

Question 32

What is the mode?

Answer 32

Value that occurs most frequently, can be used with all types of data

Question 33

What is the only measure of central tendency that can be used with nominal data?

Answer 33

Mode, measure there can be no mode or more than 1 mode

Question 34

What is the median?

Answer 34

The middle, (n+1)/2 when ordered by smallest to largest

Question 35

In ordinal data or finite set the interval/ratio data is what?

Answer 35

Median

Question 36

What are the properties of Median?

Answer 36

Uniqueness: there is only one for a data set Simplicity: easy to calculate Not as drastically affected by extreme values

Question 37

What is Arithmetic Mean?

Answer 37

Interval and Ratio Data Add all the values and divide by the total number of values

Question 38

What is the terminology for Arithmetic Mean?

Answer 38

μ = population mean Σ = sum Xi = individual observations N = population size X̄ = sample mean n = sample size

Question 39

What are the properties of the mean?

Answer 39

Uniqueness: only one for a given data set Simplicity: easily understood and easy to compute Every value in a set of data enters into computation, it is affected by each value

Question 40

What is the range?

Answer 40

Difference between the highest and lowest values

Question 41

Is range a good or poor measurement of dispersion?

Answer 41

Usefulness is limited since it only takes two values into account = POOR measure

Question 42

What is the Interquartile Range IQR?

Answer 42

Reflects the variability of the middle 50% of the observations

Question 43

What is the formula for IQR?

Answer 43

Qu - Ql or Q3-Q1

Question 44

What is Qu or Q3?

Answer 44

Median of upper half

Question 45

What is Ql or Q1?

Answer 45

Median of lower half

Question 46

Is IQR a good or poor measurement of dispersion?

Answer 46

Less affected by a few extreme scores = MORE USEFUL measure

Question 47

What is the Variance?

Answer 47

Measures the dispersion relative to the scatter of the values about their mean

Question 48

How does dispersion affect Variance?

Answer 48

Values that lie close to their mean = decreased dispersion If you have 2 dispersions with the same mean number the distribution of the dispersion determines the variance

Question 49

What is the formula for Variance?

Answer 49

Sample Variance = (1 point in the set - sample mean) ^2 Take all those points and divide by the total number of points in the set n (sample size)

Question 50

What is Standard Deviation?

Answer 50

The square root of the variance Simply square root the variance to find SD

Question 51

What is the difference between Sample SD and Population SD?

Answer 51

The denominator, the "n" vs "N" Use 'n' sample size for Sample SD or use 'N' population size for Population SD

Question 52

What is the measure of central tendency for Nominal Data?

Answer 52

Mode

Question 53

What is the measure of dispersion for Nominal Data?

Answer 53

Index of Dispersion 0 = when all ratings fall into 1 category 1 - when all ratings are equally divided among categories

Question 54

What the measure of central tendency for Ordinal Data?

Answer 54

Mode or Median

Question 55

What is the measure of dispersion for Ordinal Data?

Answer 55

Range or IQR

Question 56

What is the measure of central tendency for Interval Data?

Answer 56

Mean, Median, or Mode

Question 57

What is the measure of dispersion for Interval Data?

Answer 57

Range, IQR, or SD

Question 58

What is the measure of central tendency for Ratio Data?

Answer 58

Mean, Median, or Mode

Question 59

What is the measure of dispersion for Ratio Data?

Answer 59

Range, IQR, or SD

Question 60

What is Negative Skewness?

Answer 60

The long 'tail' is pointing towards the negative numbers

Question 61

What is Positive Skewness?

Answer 61

The long 'tail' is pointing towards the positive numbers

Question 62

How is M/M/M ranked in negatively skewed data?

Answer 62

Mode > Median > Mean

Question 63

How is M/M/M ranked in positively skewed data?

Answer 63

Mean > Median > Mode