1.6 Intended audience

We aim for three broad audiences:

• Professionals in the field of child growth and development;
• Policymakers in international settings;
• Statisticians, methodologists, and data scientists.

Professionals in child development will become familiar with a new approach to measuring child development in early childhood. We plan to separate the measurement instrument from the scale used to express the result. This formulation allows the user to select the instrument most suited for a particular setting. Since instruments differ widely in age coverage, length, administration mode, and domain coverage (Boggs et al. 2019), the ability to choose the instrument, while not giving up comparability, represents a significant advance over routines that marry the scale to the instrument.

Policymakers in international settings wish to know the effect of different interventions on child development. Gaining insight into such effects is not so easy since different studies use different instruments. The ability to place measurements made by different instruments onto the same scale will allow for a more accurate understanding of policy effects. It also enables the setting of priorities and actions that are less dependent on the way the data were collected.

Statisticians and data scientists generally prefer numeric values with an unambiguous unit (e.g., centimeters, kilograms) over a vector of dichotomous data points. This chapter shows how to convert a series of PASS/FAIL scores to a numeric value with interval scale properties. The existence of such a scale opens the way for the application of precise analytic techniques, similar to those applied to child height and body weight. The techniques have a solid psychometric backing, and also apply to other types of problems.