I am a researcher in cognitive psychology studying object locations respective to a landmark. I have the error (distance between the real position of the object and the position where the patient put it) and the angle relative to the landmark (that computed between the real position of the object and the position where the patient put it).
So an ideal case would be an error of 0 cm and an angle of 0°.
However, these two measures used alone do not grasp the whole performance. I can have an angle of 10° and an error of 2 or an angle of 10° and an error of 20. In this case, I used the landmark well but my memory for the location was bad...or by using the error, I only have a measure of the memory for that location but any (objective) information on how I used the landmark (which is my main study aim).
How, mathematically, can I combine these two measures? Any other suggestions Would be error*angle a good formula?
Many thanks