Normalised choice aims to solve the paradox that segregated designs add more total (and average) choice to the system than integrated ones. It divides total choice by total depth for each segment in the system. This adjusts choice values according to the depth of each segment in the system, since the more segregated is, the more its choice value with be reduced by being divided by a higher total depth number. This would seem to have the effect of measuring choice in a cost-benefit way.
Normalised angular choice
Hillier, B., Yang, T., Turner, A., (2012) Advancing depthmap to advance our understanding of cities. In: Greene, M and Reyes, J and Castro, A, (eds.) 8th International Space Syntax Symposium. Pontificia Universidad Catolica de Chile: Santiago, Chile.