practical science key terms Flashcards
when is a measurement valid?
when it measures what it is supposed to be measuring
when is a result accurate ?
when it is close to the true value
what are precise results?
when repeat measurements are consistent or agree closely with each other
what is repeatability?
how precise repeated measurements are when they are taken by the same person using the same equipment under the same conditions
what is reproducibility?
how precise repeated measurements are when they are taken by different people using different equipment.
what is the uncertainty of a measurement?
the interval within which the true value is expected to lie.
define measurement error.
the difference between a measured value and the true value
what type of error is caused by results varying around the true value in an unpredictable way?
random error
what is a systemic error?
a consistent difference between the measured values and true values.
what does zero error?
a measuring instrument gives a false reading when the true value should be 0.
what variable is changed or selected by the investigator?
independent variable
what is a dependent variable?
a variable that is measured every time the independent variable is changed.
define a fair test.
a test in which only the independent variable is allowed to affect the dependant variable
what are control variables?
variables that should be kept constant to avoid them affecting the dependant variable.
