Because anemia is diagnosed by measuring hemoglobin concentration in blood, there is an urgent need to make a systematic comparison of hemoglobin concentrations using different types of blood samples from the same individuals and analyzed using different instruments. USAID Advancing Nutrition is seeking public comments on a protocol that will guide future grant awards to organizations or individuals who would like to conduct or fund primary studies to assess the variability in measurement of hemoglobin concentration. This public comment period allows interested groups or firms to contribute to the revision of the protocol and prepare to apply for the upcoming grants.