Sampling and Randomization
benefits loss [
RECRUITMENT
Funding supported 131 individuals in treatment over 2 years. A control group 200 was indicated for estimated attrition of 20% to produce a conservative minimum detectable effect. With a non-directional hypothesis, with power set at 0.80 and alpha set at 0.05, MDE was Recruitment used a stratified random sample of households within census tracts at or below Stockton’s household area median income of $46,033. Forty-two census tracts meeting criteria were selected, and Delivery Sequence File (DSF) lists were purchased from a licensed vendor. A percentage of addresses was drawn from each tract based on population proportion. A mailer to participate in SEED and research was sent to 4200 households. Mailers were addressed to households allowing anyone to respond thereby assisting in mitigating benefits loss [