#2.2.1a
systematic errors (including zero errors) and random errors in measurements
#2.2.1b
precision and accuracy
As discussed in The Language of Measurement(ASE 2010).
#2.2.1c
absolute and percentage uncertainties when data are combined by addition, subtraction, multiplication, division and raising to powers
As set out in the ASE publication Signs, Symbols and Systematics (The ASE Companion to 16–19 Science, 2000).
A rigorous statistical treatment is not expected.
#2.2.1d
graphical treatment of errors and uncertainties; line of best fit; worst line; absolute and percentage uncertainties; percentage difference.
An elementary knowledge of error bars is expected at A level.