Key Science Skills Flashcards
definition of independent variable
the factor/s that is/are
manipulated in an experiment
definition of dependent variable
the factor/s measured in the experiment that are changed when
the IV is manipulated
definition of controlled variable
a factor that is kept constant throughout the
experiment
definition of qualitative data
information that cannot be counted, measured or easily expressed using numbers
definition of quantitative
are data represented numerically, including anything that can be counted, measured, or given a numerical value
definition of personal errors
Mistakes or miscalculations made by the experimenter.
Counting incorrectly, rounding to the wrong decimal place, or
labelling samples incorrectly are all examples of personal errors
definition of random errors
Errors which are caused by unpredictable variations in the measurement process and result in a spread of readings.
definition of systematic errors
Errors which cause results to differ from the true value by a consistent amount each time, typically due to faulty equipment or calibration. They affect the accuracy of the experiment, and
cannot be minimised through replication.
how to avoid personal errors
Repeat the experiment again. For measurements relying on human accuracy (e.g. counting plant numbers), you can get two or three people to make the same measurement.
how to avoid systematic errors
Re-calibrate your instruments, or use more reliable equipment.
how to avoid random errors
Replicate the experiment, increase the sample size,
refine the measurement process, or use more precise measuring equipment.
definition of accuracy
how close a measurement is to the true value
definition of precision
two or more measurements that closely align with each other
definition of validity
a measurement or
experiment that actually tests what it claims to be testing
definition of repeatability
an experiment/
measurement in which scientists, using the methods they designed,
can obtain the same result multiple times
