Examine the information in Table II and Figure 2, and see if you can answer the following questions:
- Which hemoglobin category contains the most observations?
- How many women had a hemoglobin between 12 and 13 gm/dL?
- How many women had a hemoglobin greater than 12 gm/dL?
- How many had a hemoglobin of greater than 13, but less than 15 gm/dL?
Answers: the category 12 - 14 had the most observations, and 35 women (25+9+1) had a hemoglobin count greater than 12. However, questions 2 and 4 cannot be answered with the information presented.
You can see that the process of grouping the information into categories can result in the loss of some information, but for most purposes the benefits of readability outweigh the information loss.