  Honour based abuse covers a wide range of family abuse including female
genital mutilation and forced marriage. Safeguarding professionals need to
identify where abuses are happening in their local community to best support
those at risk of these crimes and take preventative action. However, there is
little local data about these kinds of crime. To tackle this problem, we ran
comparative judgement surveys to map abuses at local level. In previous
comparative judgement studies, participants reported fatigue associated with
comparisons between areas with similar levels of abuse. Allowing for ties
reduces fatigue, but increase the computational complexity when fitting the
model. We designed an efficient Markov Chain Monte Carlo algorithm to fit the
model, allowing for a wide range of prior distributions on the model
parameters. Working with South Yorkshire Police and Oxford Against Cutting, we
mapped the risk of honour based abuse at community level in two counties in the
UK.
