In this video I describe how we can describe dispersion or variability in nominal data by calculating a variation ratio. This is a simple measure of spread that tells us the frequency of scores that differ from the mode, which … Read More
How to Find the Precise Median (Interpolated Median)
In this video I explain how to find the precise median for a continuous variable with many repeated scores. I walk through an example of this that can be solved visually, then use this example to derive the formula for … Read More
Understanding Central Tendency
In this video I explain the strengths and limitations of the 3 measures of central tendency: the mean, the median, and the mode. This is part of a key theme of statistics, which is the importance of the choices researchers … Read More
The Ordinal vs. Interval Debate in Psychology
In this video I describe how psychologists and social scientists often treat ordinal data as if it were interval data, which is a cause of some debate between pure statisticians and more pragmatic researchers. I discuss why this may or … Read More
Is Peripheral Vision in Color or Black and White?
In this video I discuss peripheral color vision, including the common misconception that peripheral vision is completely black and white. By looking at the distribution of rods and cones throughout the retina, we can see that color vision extends to … Read More