Researchers said the survey would provide a "reality check" on practices in the workplace.
The survey will help the department have a better understanding of its homeless population and provide more accurate statistics.
The survey results also often provide strong information even when there is not a statistically significant difference.
She said the survey provided a "strong message" that there was an appetite for change.
Aerial surveys can provide information on many things not visible from the ground.
The survey has provided rough justice since 1970; no other system can do more.
The survey does not provide data on how many buildings have fewer than 10 units.
The survey published today also provided data on nursing home patients.
