Chapter 2 Flashcards
In any measurement, the difference between the expected (true) value and the experimental value
Absolute error
The uncertainty expressed in the same units as the measurand
Absolute uncertainty
How close the calculated value is to the true or accepted value; includes components of trueness and bias
Accuracy
The difference between an experimentally determined value and an accepted true value; quantitative expression of trueness
Bias
An expression of the standard deviation of a relatively small data set adjusted by the use of the student t value
95% confidence interval (95% CI)
A hypothesis test to identify outliers
Dixon’s test
The difference between an accepted value; bias. Error isn’t the same thing as uncertainty
Error
A hypothesis test to identify outliers
Grubbs test
Statistical tests that compare two quantities, one calculated and one tabulated to determine the acceptance or rejection of a hypothesis
Hypothesis testing
That which is being measured
Measurand
The science of measurement as a general topic
Metrology
A notational system for the management and communication of uncertainty in science for policy; numeral-unit-spread-assessment-pedigree
NUSAP
A sample result that appears to be unusually far from the mean in a normal distribution; can be evaluated using significance tests
Outlier
The larger group of possible measurements from which a subset is drawn; has N number
Population
Reproducibility of replicate measurements
Precision
A technique that combines uncertainties from individual steps to obtain an estimate of the uncertainty of a process
Propagation of uncertainty
Errors that are not the same, not reproducible, equally plus and minus, and generally small
Random error
The degree of trustworthiness of data
Reliability
Uncertainty contribution expressed as a fraction or percentage
Relative uncertainty
Statistical tests that compare two quantities, one calculated and one tabulated, to determine the acceptance or rejection of a hypothesis
Significance test
These arise from the instrumentation and consist of every digit that is certain plus the first uncertain one
Significant figures
The average deviation of all points in a data set from the mean of that data set
Standard deviation
Errors that are the same size and magnitude each time; reproducible errors
Systematic error
An error in which the null hypothesis is incorrectly rejected
Type I error
An error in which the null hypothesis is incorrectly accepted
Type II error
The range or expected spread around a measurand that arises from the sample, analyst, procedure, or other factors; doesn’t imply lack of trust or knowledge; it is a description of a range
Uncertainty
A description of how useful information or data is to answering a specific question at hand
Utility
The square of the standard deviation
Variance
