For recipient cases, random assignment can occur either at a single point in time (when the welfare reform policies are first introduced in the research sites) or over time (as ongoing cases go through the redetermination process).
The chief advantage of random assignment at the time of redetermination is that, immediately following random assignment, cases can be informed in person of their experimental or control status. The provision of this information in person will ensure that recipients are informed of the programs and rules that apply to them and avoid any confusion about the policies to which they are subject.
The chief disadvantage of sampling recipients at the time of redetermination is that this approach excludes cases that do not remain on assistance long enough to reach this point. For example, when assignment occurs at redetermination, the recipient sample may include no cases that have been on assistance for less than six months.