Introduction

Before considering how the performance of public services should be measured, it is important to step back a little and think about some of the issues underpinning this measurement. We first need to consider a very basic question: why do we measure anything? I started writing this chapter during a visit to New Zealand and, strange though it may seem, the garage walls of the house I rented for my stay hint at part of the answer. One wall has a series of pencil lines drawn at different heights, each accompanied by a date and a name. The names are those of the children who grew up in the house, whom I’ve never met. The lines record their heights as they grew from small children towards their teenage years. Their height is one element of the progress that the children made as they grew through childhood. The marks on the wall form a simple measurement system to show how the children developed.

Consider another mundane example: the weight of babies is routinely monitored during their first months of life. Mothers are often given a card on which the weights are recorded, and many families retain these cards as mementoes long after they are needed for their original purpose. The weighing and recording enables doctors, nurses and other advisors to see whether the baby is gaining weight as she should. Though knowing the actual weight of a baby at a point in time is important, there is another reason for keeping this record. This is that it enables parents and medical staff to see the trend in weight since the child’s birth because, just as adults have different body shapes and weights, so do babies. If this trend gives cause for concern, the baby may need special care, or the parents may need advice and support in appropriate ways to feed the child. That is, the weight record forms the basis for assessing progress and for deciding whether intervention is needed.