Bill also keep in mind that there isn't a big cliff where you fall off the strip ailerons down to the barndoor ailerons effectiveness and side effects. Visualize a image of going from one to the other (kinda of motphing a good guy into the werewolf in the movies). As each of the parameters is incremented - span, chord, position, etc. - the resulting roll and yawing moment also changes.

We tend to build the strip aileron because it is easy, or, if we don't mind doing the building thing, we make a barndoor installation - so we think of them as either/or. You can indeed make a aileron that is 3/4 span and 15 percent chord that is inbetween that has the good or bad characteristics of each.

At one time, 20 years ago, I had summarized the appropriate graphs to let a person make an estimate of aileron effectiveness but can't find them anywhere now. But the curves with respect to span and chord of aileron sizes were smooth variations.