Nonsampling errors are errors in response or coding of responses and nonresponse errors or incomplete sample frames. The study design is such that, in States with a monthly sample of about 200 cases, an estimate of 50 percent should not vary from the true value being estimated by more than 6.9 percentage points at the 95 percent confidence level. California is the State with such a small sampling fraction. To obtain the 95 percent confidence level at each percent in Table II, multiply the standard error by a factor of 1.96. To obtain the 99 percent confidence level, multiply the standard errors by a factor of 2.58.
Every effort is made to assure that a list of the universe or the sample frame is complete.
It is possible, however, that some cases receiving assistance for the reporting month are not included. There is no measure of the completeness of the universe. Data entries are based on information in the case records. Errors may have occurred because of misinterpretation of questions and because of incomplete case record information. Errors may also have occurred in coding and transmitting the data.