5.1 Beginning at the end
The approach we’ll use in this Chapter will be to start off by showing you a figure which we suggest is at a standard that you could use in a poster or presentation. Using that as the aim, we will then work towards it step-by-step. You should not view this final figure as any sort of holy grail. For instance, you would be very unlikely to use this in a publication (you’d be much more likely to use some results of your hard earned-analysis). Regardless, this “final figure” is, and will only ever be, a reflection of what our personal preferences are. As with anything subjective, you may well disagree, and to some extent we hope you do. Much better that we all have slightly (or grossly) different views on what a good figure is - otherwise we may as well go back to using cookie-cutter figures.
So what’s the figure we’re going to make together?
Before we go further, let’s take a second and talk about what this figure is showing. On the y axes of the four plots we have the surface area taken up by a flower shoot, and the x axes show the weight of a flower. Each column of multiples (the name for each individual plot) shows the two treatments used in the experiment (whether the tip of the flower was cut off or not) and the two rows show which block of the greenhouse the plants were grown in (block 1 or block 2).
The different coloured and shaped points represent the three nitrogen concentration levels used in the experiment. These colours are used to distinguish which points correspond to a certain nitrogen concentration.
Added to the plots we also have four trend lines (produced by linear regressions, see Chapter 6). The three coloured solid lines show the relationship between shoot area and weight of the flower. These coloured lines are inturn specific to each “facet” in the grid and change acording to treatment and block. The dashed black line represents the relationship between shoot area and weight while ignoring any nitrogen affect.
The final line, the thin dotted grey line, shows the mean shoot area regardless of the weight of the flowers, the nitrogen concentration, the treatment or the block.
For the purposes of this Chapter, we won’t worry about the biology here. Do not take this to be standard, you should absolutely care deeply about the science in your own data. It’s the science that should be the driving force behind the questions you ask, which in turn determines what figures you should make.