Evaluating your measurement tool

Question 1

What is content validity

Answer 1

When the instrument used is designed to accurately measure the concepts under study

Question 2

What is convergent validity

Answer 2

When the results obtained are similar to the results obtained with another previously validated test that measures the same thing

Question 3

What is correlation coefficient

Answer 3

A test value used to determine how closely one measurement is related to a second measurement

Question 4

What is divergent validity

Answer 4

When the measurement of the opposite variable of a previously validated measurement yields the opposite result.

Question 5

What is efficiency (EFF)

Answer 5

Measures the probability of agreement between the screening test and the actual diagnosis

EFF = (A + D / A + B + C + D) x 100

A = true positives

B = # of positive tests

C = # of false negatives

D = true negatives

Question 6

What is equivalance

Answer 6

How well multiple forms of an instrument or multiple users of an instrument produce the same results

Question 7

What is homogeneity

Answer 7

The extent to which the properties of any part or variable of an overall data set are the same as any other part.

Question 8

What is internal consistency reliability

Answer 8

Homogeneity of the measurement instrument. OR a reliability measurement in which items on a test are correlated in order to determine how well they measure the same concept or construct.

Question 9

What is inter-rater reliability

Answer 9

When you compare the measurements obtained by two different data collectors to make sure they are similar

Question 10

What is reliability

Answer 10

The consistency or repeatability of the measurement

Question 11

What is predictive validity

Answer 11

When the instrument used accurately suggests future outcomes or behaviors

Question 12

Cronbach’s alpha

Answer 12

Represents the internal consistency reliability on a scale of 0 to 1 where 0 is no reliability and 1 is perfect reliability

Question 13

What is readability

Answer 13

affects both the validity and reliability of an instrument

Question 14

What is validity

Answer 14

accurate measurement and collection of data

Question 15

What is stability

Answer 15

the consistent or enduring quality of the measure. It should not change over time and be consistent when tested repeatedly.

Question 16

Accuracy of a screening test is determined by

Answer 16

the tests ability to identify subjects who have the disease and subjects who do not.

Question 17

What is sensitivity

Answer 17

the probability that a test subject with a disease will test positive Sensitivity = A / A + C A = true positives C = all who have the disease (including those who test negative)

Question 18

What is specificity

Answer 18

the probability that a well subject will have test negative on the screen (no disease)

Specificity = D / (ß + D)

D = true negatives

ß = All those who do not have the disease, even if they test positive

Question 19

What is the positive predictive value

Answer 19

(PPV) tells you what the probability is that a subject actually has the disease given a positive test result

PPV = A / (A + B)

A = true positives

B = number who tested positive

Question 20

What is prevelance

Answer 20

the amount of illness (# of cases) present in the population divided by the total population

Prevalence = A + C / A + B + C + D

A = true positives

B = # who tested positive

C = # of false negatives

D = True negatives

Question 21

What is negative predictive value

Answer 21

the probability that a negative screen result represents absence of the disease. NPV = D / (C + D)

D = true negatives

C = False negatives

Question 22

What is central tendency

Answer 22

The indicator for the center of a dataset as either mode, median, or mean.

Question 23

What is mode

Answer 23

The most frequently occurring measure(s) in a dataset.

Unimodal - one most frequent value

Bimodal - two equal most frequent values

Multimodal - > 2 most frequent values

Question 24

What is the median

Answer 24

The middle value when values are listed from least to greatest. Note: if there are an equal number of values the median is the average of the two middle values.

Question 25

What is the mean

Answer 25

The mean is the average of the values in a dataset (susceptible to outliers)

Question 26

What is the range

Answer 26

The difference between the least and greatest values

Question 27

What is the standard deviation

Answer 27

The average distance from the variables mean. (ð)