measurement principles Flashcards
definition: the process of value assignment
measurement
definition: characteristics of indiv., objects, or environmental conditions that may have one or more values
variables
definition: the value that is purposefully manipulated by researchers in a research study to produce a change in outcome (x axis)
independent variable
(true/false) intervention studies can only have one independent variable
FALSE (they can have multiple)
definition: the outcome of interest in a study (Y axis)
dependent variable
definition: a factor other than the independent variable which may influence or confound the dependent variable
Ex: multiple investigators, subjects, new equipment, environment
extraneous variables
definition: a variable that can only be measured in separate units and that cannot be measured in intervals of less than one
discrete
definition: when only two values are possible
dichotomous
definition: a quantitative variable that can theoretically take on values along a continuum
continuous
What are the four levels of management?
nominal, ordinal, interval, ratio
Give an example(s) of nominal measurements.
sex, nationality, blood type
Give an example(s) of an ordinal measurement.
MMT, pain
Give an example(s) of an interval measurement.
calendar years, IQ, centigrade
Give an example(s) of a ratio measurement.
distance, age, time, weight
definition: interpretation of a score based on its value relative to a standard or “normal” value
norm-referenced
definition: interpretation of a score based on its actual value
criterion-referenced
definition: the difference between the true value and the observed value
measurement error
definition: predictable errors of measurement
systematic error
definition: error due to change and is unpredictable
random error
definition: the degree to which test scores are free from errors of measurement; the amount of variability in a measure
reliability
definition: measures the consistency of measurement values between different individual raters
inter-rater reliability
definition: measures the consistency of measurement values of one individual
intra-rater reliability
definition: the ability of a measurement to capture what it was intended to capture
validity
definition: is it appropriate to measure the variable using the selected instrument?
face validity
definition: all relevant components of a variable are measured by the instrument
content validity
definition: the ability of a measure to represent the concept/construct being evaluated
construct validity
definition: the degree to which instrument scores relate to a reference standard instrument’s scores
criterion related validity
definition: the degree to which an instrument can distinguish between or among different concepts/constructs
discriminant validity
definition: refers to the degree to which two measures demonstrate similar results
convergent validity
defintion: validity that is used when tests are administered at the same time and can replace another test
concurrent validity
definition: how a test predicts from a reference standard
predictive validity
What Intraclass correlation coefficient (ICC) is an indication of excellent reliability?
> 0.9
What Intraclass correlation coefficient (ICC) is an indication of poor reliability?
< 0.5
What statistic accounts for chance agreements?
Kappa statistic (cohen’s)
What value is considered as excellent agreement using kappa statistic?
> 0.8
What value is considered as fair-poor agreement using kappa statistic
< 0.4
definition: the # of exact agreements / number of possible agreements (the closer to 100%, the better)
percent agreement
What tests are used for testing the association of 2 measures?
pearson, spearman
What value is considered as little to no association when using pearson and spearman tests?
0.0-0.3
What value is considered as good to excellent association when using pearson and spearman tests?
0.75-1.00
What is the equation for finding the coefficient of variation?
CV= SD/ mean
