Category Archives: R Scientific figures are at their most informative when they include the individual data used to calculate summary statistics such as means and standard deviations. Why is showing data important? As previously pointed out here and here, figures with means, standard deviations, standard errors, etc. can be misleading and conceal the nature of the underlying data. As highlighted in our previous

Independent t-test as a linear model in R My last two posts have shown how to perform an independent t-test in the R programming language and the Python programming language. For those of you who are familiar with statistics, you likely know that an independent t-test is equivalent to performing an one-way analysis of variance on the data. What you may not have realised is that both these

Independent t-test in R As scientists, we often want to know if the difference between two groups is important or significant. For example, you may have data on leg strength from students who came to class wearing dress shoes or running shoes. How would you decide if there was a difference in strength between these two groups? How would you quantify the size of

R: Analysing small datasets – Part 3 In the previous post, when repeated measures data from 10 subjects in 2 conditions were compared, it seemed that subjects who took drug 1 slept fewer hours compared to when they took drug 2. How might we test whether the median number of hours of sleep after drug 1 is less than after drug 2? We can calculate the difference

R: Analysing small datasets – Part 2 In the previous post we plotted repeated measures data from 10 subjects under 2 conditions. There are different ways to analyse small datasets. We could apply parametric methods to analyse the data values, such as describing the data with means and standard deviations, and calculating a paired difference. Or, we could also apply non-parametric methods by analysing data values based 