ABSTRACT
The measurements that do not have a metric, such as site of injury (“measured” as head, chest, abdomen, etc.) and blood groups (measured as O, A, B, and AB), are called qualitative measurements. This is in contrast to quantitative measurements such as blood pressure, hemoglobin, creatinine, and size of kidney, which are measured in numeric metric. Qualitative measurements could be dichotomous or polytomous depending on whether the number of categories is two or more than two, and polytomous could be further divided into ordinal (such as the severity of disease being mild, moderate, serious, and critical) and nominal (with no order, such as site of cancer).
