In mathematics, specifically advanced statistics, bimodal refers to a continuous probability distribution (a projected probability spread) over a graph that, when calculated with different mathematical modes, show different pattern spreads.
In statistics, data, such as grades or IQs, are calculated with a single mean or mode that will produce a single point spread (hyperlink?), usually resembling a bell/normal curve. However, when calculating the same data using the other mean or mode will produce a different point spread with a different bell curve. This information is not commonly used except in high level research.