Sample. As already noted, by a congressional mandate, HUD is requiring local communities to develop a computerized data collection system. Since 2001, HUD has been working with local jurisdictions to develop and implement the HMIS. Individual CoCs will soon be required to submit information to HUD electronically based on Federal HMIS guidelines published in July 2004. These guidelines outline a set of universal elements that every CoC will be required to collect on all persons receiving homeless services, more detailed information that needs to be collected on everyone receiving services through McKinney-Vento-funded programs, along with a set of additional, recommended data elements.
Individual CoCs will be required to annually submit only aggregate information to HUD, however. As noted earlier, HUD has made it clear that "the HMIS initiative will include no Federal effort to track homeless people and their identifying information beyond the local level." As a result, the Federal guidelines state that "any research on the nature and patterns of homelessness that uses client-level HMIS data will take place only on the basis of specific agreements between researchers and the entity that administers the HMIS."18 Since it would not be feasible, nor necessary, for a study to coordinate with more than 400 CoCs operating across the nation, a sample of CoCs would need to be created.
To identify CoCs to approach for being in an HMIS study, a stratified, multistage cluster sample would need to be used. The CoCs would first be clustered on the basis of geography (e.g., programs in the South or Northeast), as well as possibly by community size (total population), and estimated size of the homeless population (based on prior research). One important set of criteria would also likely be the extent to which the HMIS is operational in a community, including the number of homeless service providers participating in the HMIS effort and the extent to which detailed information is being collected on everyone in the homeless assistance system. Once various clusters of CoCs have been established based on this sort of criteria, communities could be randomly selected to provide a comprehensive national sample of CoCs and, by extension, homeless families.
This sort of multistage cluster sampling procedure has already been used to select communities involved in the first Annual Homeless Assessment Report (AHAR). Although the AHAR will eventually include information from all CoCs, a sample of 80 communities was selected to provide information for the first annual report. Of these 80 communities, 18 were chosen because they have the largest homeless populations (e.g., New York City, Chicago, Los Angeles). The remaining communities were randomly selected after clustering them by their population size and region. The result is a nationally representative sample of communities.
After a sample of CoCs has been selected, each agency administering the HMIS that agreed to participate in the study would provide client-level data to be analyzed. The data submitted could include retrospective data on people and families already served, as well as periodic updates to enable researchers to track families over time.
Time Frame. The HMIS is designed to track people and families over time and record their history within the homeless service system. As a result, it would be possible to examine families from the beginning of each community's HMIS system. In order to compare results across HMIS systems, however, a common starting point would need to be established. When to set that starting point would be a function of the implementation histories of the HMIS systems in the selected communities.
Another data collection factor that would need to be taken into account, either in selecting communities or determining the starting point for data collection, is the extent of HMIS coverage. In order to be confident in the results obtained from any analyses, the Federal Government recommends that the HMIS cover at least 75 percent of the emergency and transitional housing beds in the community. Since it may have taken each CoC some time to begin collecting information on 75 percent or more of the homeless beds, the date when information can be reliably obtained from an HMIS is, therefore, likely to be later than the date when data collection initially started.