Abstract
The previous chapter dealt with how people interpret graphics. This chapter examines how people interpret numbers, typically given as probabilities or risks (Figure 1). In a majority of HII situations, numbers are essential for gaining a full understanding of the situation. This chapter covers how people react to numbers. Since many people have a high literacy level but a low numeracy (number literacy), design teams must understand how people interact with and interpret numbers as it is essential to understanding how it affects the communication process.