# Data visualization tips for a 2x2 factorial design

The data stem from a 2x2-factorial design where both factors have two levels. The x-axis shows the words of a sentence and the y-axis the mean reaction time for each single word. Here is how I visualize the data so far with base R:

I find the usual method of visualizing such data rather unappealing but I couldn't come up with a nice idea myself. Are there more appropriate ways of summarizing such data in one single plot?

• What are the bars above and below the points? What are the stars? They need to be described or removed. Why is the axis broken when there are no points below the break, and the scale doesn't seem to actually break there? – shadowtalker Feb 28 '15 at 13:25
• And if there's any kind of natural (read: substantively relevant) ordering on the x-axis, you should use it. BTW I'm posting these as comments and not answers because they don't really relate to 2x2 experiments, but I think they do need to be addressed – shadowtalker Feb 28 '15 at 13:29
• The bars are error bars according to Cosineau (2005). The stars show significance but don't really matter here as this is random data. The scale with the original data is broken between 0 and a larger number. In short: This is a pure dumb plot only in existence to illustrate the problem without a lot of words. It obviously lacks the precision one would wish for. – lord.garbage Feb 28 '15 at 13:34
• my suggestion stands: label it or drop it. Also, don't break plots just to get 0 in there, unless 0 is an important reference point for this data (and usually it isn't) – shadowtalker Feb 28 '15 at 14:08
• I agree with the labeling but error bars et. al. I would outsource to a figure caption. The breaking-the-axis-part is controversial so we probably won't settle this here. Thanks for the tips. – lord.garbage Feb 28 '15 at 14:12