I have collected psycophysiological data measuring the subjects (two groups) ability to perceive vibration. A vibrating probe moves against the skin at smaller and smaller displacements, and the subject indicates when they feel the vibration. Unfortunately, at high frequencies, the probe can only move a short distance, and sometimes the largest distance that the probe can move is still not large enough for the subjects to perceive. Thus, I have accurate threshold values for some subjects, but for some who never felt the vibration, I simply have a value that I know their threshold is greater than. Is there any way for me to still include this data? And what is the best way to analyze it?
Clustering the results and defining a scale might be a solution.
Make a category variable like so (or differently):
You could use this variable to do the analysis, but whether the results are meaningful depends on how well you define the categories.