How would I know if I need a 2D or a 3D map?

3D maps are more difficult to visually interpret than 2D maps. Therefore, if we have an adequate 2D map (e.g., more than 70% of the variance in the data is captured by the map), it pays to carefully evaluate the positioning implications from the 2D map.

In some cases, however, incorporating the third dimension into the map may reveal opportunities (especially for a smaller share brand/product).

If the incremental variance (on a scale of 0 to1) explained by including the third dimension is less than the variance attributable to a single perceptual variable (= 1/n, where n is the number of perceptual variables), then a 2D map is more than adequate for the analysis.