The Effectiveness of Categorical Variables in Discriminant Function Analysis

A preliminary study of the feasibility of using categorical variables in discriminant function analysis was performed. Data including both continuous and categorical variables were used and predictive results examined. The discriminant function techniques were found to be robust enough to include the use of categorical variables. Some problems were encountered with using the trace criterion for selecting the most discriminating variables when these variables are categorical. No monotonic relationship was found to exist between the trace and the number of correct predictions. This study did show that the use of categorical variables does have much potential as a statistical tool in classification procedures. (50 pages

Assessment of efforts to reduce nonresponse bias: 1996 Survey of Income and Program Participation (SIPP)

Im Vorfeld der neuen Welle des SIPP 1996 tauchten Bedenken in Hinblick auf eine zunehmende Tendenz zur Antwortverweigerung in den Panelwellen der Jahre 1991 bis 1993 auf. Gleichzeitig wurde die Existenz eines Bias in den SIPP-Zeitreihenschätzungen zu Armut bekannt. Das US Census Bureau hat viel Zeit und Geld darauf verwandt, den Anteil der Antwortverweigerung zu reduzieren und die hierauf beruhende Fehlgewichtung zu korrigieren. Die Verfasser geben einen Überblick über diese Maßnahmen und diskutieren deren Wirksamkeit mit Blick auf das erste Jahr der Panelwelle 1996. Sie setzen sich mit dem Einsatz finanzieller Anreize, der Durchführung von Untersuchungen zur Antwortverweigerung sowie Veränderungen in der Durchführung der Feldforschung auseinander. (ICEÜbers)"Concern over increasing levels of nonresponse in the 1991-1993 SIPP Panels and new information about the existence of bias in time series estimates of poverty front the SIPP surfaced prior to fielding the newly redesigned SIPP 1996 sample. A tremendous amount of effort and expense has been dedicated by the U.S. Census Bureau to reducing nonresponse and adjusting for its bias. This paper will summarize these efforts and provide a preliminary assessment of the success of the efforts for the first year of the 1996 panel. The authors will discuss the use of monetary incentives, fielding nonresponse surveys, and changes in field staffing and procedures." (author's abstract

American Community Survey overview and the role of external evaluations

In 2010 the U.S. Census Bureau will achieve its goal of eliminating the long form sample from the decennial census and will produce its first set of five-year data products from the full sample American Community Survey (ACS). This paper provides an overview of the call for change that prompted the Census Bureau to pursue the development of a new approach to collecting socioeconomic and housing data. The paper details the evolution of the ACS from its earliest origins to its current design and describes that design in detail. The current design has benefited from external debate and consultation. Work such as that described later in this journal exemplifies the key role that external users and advisors have played, and will continue to play, in the evolution of the ACS. Over the past 10 years, the Census Bureau has undertaken research and testing to demonstrate operational feasibility and to assess survey quality. Research has also compared ACS and Census 2000 data. ACS staff are involved in survey improvement efforts and continue to confront survey challenges. In the next few years the ACS will give priority to developing user tools to aid all users in the correct interpretation of multi-year estimates. The ultimate validation of the ACS is, however, in the hands of users. Continued input from the people who are responsible for administering and evaluating programs, identifying local needs, and planning for the future will allow the ACS to grow in value and utility. Copyright Springer Science+Business Media B.V. 2006American Community Survey, Data users, Decennial census, Demographic data,