Distances (i.e., D_{1}, D_{2} or D_{3}) need not be linear functions of responses. To reflect non-linear perceptions, PCI_{2} allows for powers of distances.

**Power 1** (i.e., P_{1}, the unsquared version) is currently recommended and is the default, but any power > 0 can be used.

**Power 2** (i.e., P_{2}, the squared version) gives more weight to larger differences between individuals. If the initial difference scores were 1, 2, and 3 (i.e., P_{1}), squaring the differences (i.e., P_{2}) results in distances of 1, 4, and 9.