Graphs and tables good practice Tables Clear table

Graphs and tables – good practice

Tables

Clear table with headings and units in each column • Where possible only one table is required. • If it is to be split into two (too big for the page) it is better for the second table to contain the data they are going to plot (e. g. log values). • Headings are required for all columns we do not accept just ‘trial / reading 1, 2. . . etc. • An over riding heading with units followed by trial / reading 1, 2 is acceptable.

Clear table with headings and units in each column • Units are required for all columns and also for the resolutions of the instruments. • Log values should not have units. • Resolutions of instruments can be stated along with the headings ( or above/ below the table).

Significant figures • All raw results should be given to the same accuracy as the resolution of the instrument. • All mean values should be given to the same number of significant figures as the raw data. This should be consistent within the column unless a new factor of ten is gained / lost e. g. some data goes below one or some goes above ten.

Significant figures • Log values should be given to 2 / 3 significant figures ( beyond 3 would be impossible to plot and only 1 s. f. would mean you can’t distinguish between certain values). • We prefer candidates to use natural logs (ln, loge). We accept candidates who use log 10 but the heading must be labelled as log 10.

Other comments • For the experimental task we expect candidates to carry out repeat readings either 2 or 3 times depending on the length of the experiment. • For most experiments we expect a minimum of 5 sets of readings to enable a suitable graph to be drawn. ACTIVITY – mark exemplar tables.

Graphs

Titles and units on both axis • No unit if log values are being plotted. • Error carried forward is applied if the units were incorrect in the table. • The type of log being used is needed.

Suitable scales • The points plotted along with the error bars (if needed) should take up more than half the graph paper available. • Multiples of 3 should not be used as a choice of scale. • All points including their error bars should fit on the graph paper available. • Candidates can plot in portrait or landscape mode.

All points plotted correctly / lines of best fit • All points including their error bars should be plotted correctly to within one small square on the graph paper. This maybe awarded 1 or 2 marks with one mark being deducted for an incorrect point / error bar to a maximum of the marks available. • Lines of best fit are easier to explain using specific examples. Activity – mark typical candidate responses from the summer 2019 paper.

Any Questions?