This project will advance knowledge of how skin color can best be measured, with the objective of helping researchers identify inequalities by skin color in health and social outcomes.

Skin color has stood as a protected category since the Civil Rights Act of 1964, but our understanding of disparities by skin color is only as good as the data on skin color itself. As such, poor measurement in this case renders invisible a dimension of inequality that has been illegal for half a century. By comparing newly developed handheld devices that directly measure skin color with the most commonly-used human rating scales of perceived skin color, we will offer evidence on the relative accuracy and cost-effectiveness of the available measurement options, along with specific protocols to help researchers from a range of disciplines generate comparable measurements across future studies.

Specifically, the project will:

1. Evaluate the reliability of handheld measurement devices and of self- and interviewer-rated categorical scales of skin color;
2. Establish their validity in relation to social, behavioral, and academic outcomes; 
3. Assess the feasibility of each approach.

Our main objective is to translate technical details and jargon from the field of color measurement for use by health, behavioral, and social scientists studying the broader correlates of variation in human skin tone.

As such, our end product will be specific guidance regarding methods of skin color measurement for field-based studies, along with cost information, technical recommendations, and template research protocols and budget sheets.

By generating these resources, this project will improve both internal and external validity of skin color data, facilitating cross-sample and cross-cohort comparison — challenging tasks at present, because skin color often subjectively measured via scales that vary in format from study to study. The project will also identify the strengths and limitations of conventional skin color rating scales that primarily assess a single dimension of lightness-to-darkness, providing evidence of the need to incorporate measures of undertones (such as redness and yellowness) to better align with contemporary multifaceted and fluid conceptions of race-ethnicity. The study population will include individuals from a wide range of racial and ethnic backgrounds, drawing from our data collection site at one of the most diverse universities in the country.