low accuracy, low precision

low accuracy, high precision

high accuracy, low preicison

high accuracy, high precision

accuracy

agreement between a measured value and the accepted true value, how close would it be to the actual value

ways to express accuracy

absolute error and relative error

absolute error formula

measured value – true value

relative error formula

((measured value - true value)/(true value)) x 100%

precision

degree of agreement between replicate measurements of the same quantity

determinate errors

determinable and that presumably can be either avoided or corrected

instrumental errors

faulty equipment

example of instrumental error

uncalibrated glassware

operative errors

personal errors

example of operative error

mathematical error in calculation, misread of menisicus

errors of the method

wrong method for an experiment

example of error of the method

coprecipitation of impurities

indeterminate errors

accidental or random errors

what does indeterminate error show in a distribution?

bell curve or normal distribution

significant figures

the number of digits necessary to express the results of a measurement consistent with the measured precision

significant figure rule in addition and subtraction

use least significant decimal place

significant figure rule in multiplication and division

use least significant figures