Contents
Which error bar is most reliable?
The reliability of the mean value as a representative number for the data set. In other words, how accurately the mean value represents the data (small SD bar = more reliable, larger SD bar = less reliable).
How do you choose error bars?
I mentioned that you can choose three options for the length of the “error bars”: the standard deviation of the data, the standard error of the mean, or a confidence interval for the mean.
How do error bars show reliability?
The length of an Error Bar helps reveal the uncertainty of a data point: a short Error Bar shows that values are concentrated, signalling that the plotted average value is more likely, while a long Error Bar would indicate that the values are more spread out and less reliable.
Error bars can communicate the following information about your data: How spread the data are around the mean value (small SD bar = low spread, data are clumped around the mean; larger SD bar = larger spread, data are more variable from the mean).
When to look for overlap between error bars?
Look for overlap between the standard deviation bars: When standard deviation errors bars overlap quite a bit, it’s a clue that the difference is not statistically significant. You must actually perform a statistical test to draw a conclusion.
What is the p value of error bars?
In Experiment 1, there is no overlap in the standard error bars. Thus, the p -value would be greater than 0.05 and hence, it can be concluded that the difference is not statistical significant. But, in experiment 2, the error bars overlap and the sample sizes are equal. Hence, the p -value is less than 0.05.
What should you use for the heights of the error bars?
A line connects the means of the responses at each time point. A box plot might not be appropriate if your audience is not statistically savvy. A simpler display is a plot of the mean for each time point and error bars that indicate the variation in the data. But what statistic should you use for the heights of the error bars?