For a long time there was great debate over how to accurately describe homelessness and its pervasiveness into American culture. There are two well recognized ways to describe homeless numbers:

• Point in time: measuring the number of homeless people at any one given time. A “snapshot” of homeless numbers. “Critics say this method is likely to overestimate the number of chronically homeless and underestimate the number of people who experience temporary homelessness.”

• Period prevalence: recording homeless numbers over a set period of time. “Critics of this method point to the difficulty of standardizing measurements. Other affecting factors in measuring homeless rates include the duration of counting and time of year of counting.”

HUD has adopted a modified point-in-time method that measures homeless numbers in shelters and homeless numbers on the streets. After a thorough examination of numbers in 2005, HUD came up with a baseline of over 744,000 homeless people at any given time. This baseline number helps establish a measurement for future homelessness. Today, in 2009, we can look at the numbers and determine whether or not we have more homeless people or less than 2005.

For more information see HUD and PBS