Reliability, Precision, Accuracy and Validity

	What is it?	How can it be applied in an experiment?
Reliability	Others can repeat your experiment and get the same reulsts.	This can be attained by repeating the experiment.
Precision	How small a measurement is.	This can be attained by using measuring instruments of a smaller scale, e.g. Vernier Calliper vs. Ruler.
Accuracy	How close a measurement is to the true value.	This can be attained by reducing all errors.
Validity	You can only make a conclusion if your measurement if your measurement have been affected by an independent variable.	This can be attained by carrying out a fair test.