The U.S. Census Bureau's Data Access and Dissemination System (DADS)

The U.S. Census Bureau’s Data Access and

Dissemination System (DADS)

J. Timothy Sprehe*

The U.S. Bureau of the Census has announced its intention of making the Internet and other electronic systems the primary sources for gaining access to its statistics. The Bu- reau has begun to design the Data Access and Dissemination System (DADS) as the delivery system for the 2000 Decennial Census and ultimately as the single information

system for access to all Census statistics. On the basis of consultations with users, the

Bureau adopted a set of design principles for DADS. Most custom products available

over DADS will be fee-based. Census is also considering the use of partnerships with

private sector parties. The Bureau is also developing a metadata system for use in ac-

cessing all agency data. Data users have the opportunity to voice their views about the

design of DADS.

In August 1995, the U.S. Bureau of the Census announced: “The Internet, along with

other electronic delivery systems, will gradually become the primary sources for Census

Bureau statistics.” This announcement signaled the beginning of Census Bureau efforts to

design a new system that will deliver the agency’s statistical data to information users in

the public. The Bureau named its new system DADS-Data Access and Dissemination

System. Focused initially on the 2000 Decennial Census of Population and Housing, plus

other datasets, DADS is eventually to become one general information system for access

to all Census Bureau data and statistics. DADS is of significance, in part, because it represents one of the first major efforts by a

large federal information producer to reengineer its information dissemination program to-

ward reliance on the Internet as its basic delivery vehicle. It is also worth taking note of be-

cause the system is still in its early development stages. The Census Bureau’s strategy of

aggressive outreach to its information users means that information professionals now

* Direct all correspondence 10: J. Timothy Sprehe. Sprehe Information Management A.ssocirrtes, Inc., 1301 Penn-

svlvania Ave.. NW. Suite 507, Wushinaton, D.C. 20004-1701. <[email protected]>.

Government Information Quarterly, Volume 14, Number 1, pages 91-100. Copyright 0 1997 by JAI Press Inc. All rights of reproduction in any form reserved. ISSN: 0740-624X

92 GOVERNMENT INFORMATION QUARTERLY Vol. 14iNo. l/1997

have a window of opportunity for shaping how DADS will eventually look and for making

DADS responsive to their needs. Several factors motivated the Census Bureau to embark on the DADS design. First, the

restrictive budget climate of the late 1990s meant, among other things, that financial re-

sources will no longer be available for continuing the Bureau’s traditional publications pro: gram unchanged. In particular, emphasis on ink-on-paper products would no longer be

possible because of lack of funds for maintaining printing and distribution at past levels. In some meetings with users during 1995, Census Bureau officials had stated that when DADS was fully operational Census would no longer issue paper information products.

The immediate and explosive reaction from data users told the Census Bureau that the idea

of a paperless statistical agency was impractical at this point in history. Still, the Census Bureau has made major reductions in its printed publications program.

In July 1995, the Bureau announced a substantial list of report titles that it will no longer

print but will issue only in CD-ROM and/or over the Internet (see Table l).’ Also and as part of the budget climate, the Bureau reached the conclusion that it must

look afresh at user fees for its information products. In past years the Bureau has shown a decided reluctance to charge user fees any higher than the cost of reproduction and distri-

bution. Congress clearly signalled that the Bureau should embrace a more aggressive concept of users fees.2

Second, the rise of the Internet meant that the Census Bureau, like all other government agencies, encountered an environment in which it is possible to deliver information elec-

Table 7 Summary of Reductions in Census Bureau Publications, 1995

Subject Area

Agriculture

Construction & Housing

Decennial Census

Foreign Trade

Geography

Governments

Manufacturing & Mineral

Industries

Population

Changes Announced

One report replaced by CD-ROM

H- 111 Series available only on Internet; H-121 reduced in scope

with some tables on Internet; H-123 is discontinued

CP-3 and CH-3, Population and Housing Subject Reports: 11

reports mostly replaced by CD-ROM

FT247 and FI447 replaced by CD-ROM; FT927 consolidated with

another report

Geographic Identification Code Scheme replaced by CD-ROM

Most printed reports from Annual Survey of Governments

regarding finances and employment discontinued except for

Internet, diskette, or magnetic tape; six reports from 1992 Census

of Governments discontinued; reports on tax revenues & retirement

system finances available on Internet

Except for M3-1, MQ-Cl, and MA200, all Current Industrial

Reports available only on CENDATA, Electronic Bulletin Board,

or FastFax

P-20 series continued but significantly reduced; P-23 series reduced

in number, available in print and on Internet; P-25 and P-26 series

significantly reduced, P-26 consolidated into P-25, available on

Internet, CD-ROM and other electronic media; P-60 series

shortened and available on Internet and CD-ROM; P-70 series

content drastically shortened, available on Internet

The U.S. Census Bureau’s DADS 93

tronically in ways previously unimagined. The Bureau has found its Internet site to be ex-

ceedingly popular; by mid-1996 the site was receiving approximately one million “hits” per week. These developments motivated the Bureau’s announcement that it would shift its

information dissemination to an electronic basis. Third and perhaps most important, Census Bureau data users have been demanding de-

livery of data in a more timely, cost-effective and easily accessible manner. Choosing the

Internet as a primary delivery vehicle is seen as a direct response to this demand. The Census Bureau set for itself the working premise that the design and implementation

of DADS would be driven by close and continuous interaction with its customers. In the

fall of 1995, the Bureau convened 12 groups of users, eight external and four internal. The

external users consisted of personnel from State Data Centers and National Census Infor-

mation Centers; state, local, and tribal governments; federal agencies and Congress; busi-

ness and economic organizations; racial, ethnic minority, and rural groups; the media; researchers and academics; and librarians. Each group was formed into what might be

called a brainstorming session using a group facilitator. As advance material, each group

member received a set of guiding principles for DADS.3 The principles were as follows:

1. The system will provide direct access to a limited number of data summaries, to

public use microdata samples, and to a process for specifying special tabulations

from confidential files. It will be accessible to the widest possible array of users through the Internet and all available intermediaries, including State Data Centers

and similar groups, libraries, universities, private firms, and so forth. Internal access

through open systems is assumed. 2. There will be limited standard, prepackaged data summaries, and no standard print-

ed reports except those few profile reports necessary to show appreciation to the

public for cooperation. All access and special product preparation will be through

the dissemination system. All reports, files, etc. will be prepared on demand and rapidly, even with high demand.

3. Disclosure avoidance4 will be built into the design of the system and base files so

that the individual products from the system do not require review for disclosure.

This implies that a confidentiality edit is performed on the basic file to minimize or

eliminate additional confidentiality reviews. Work on appropriate techniques will

occur outside this group. 4. All data sources with comparable levels of geographic detail will eventually be in-

tegrated into the system (e.g., economic census files, decennial census files, and

population estimates files). 5. Geography is the integrating principle for the data, using both standard geographic

areas and nonstandard geography based on centroids or coordinates, as appropriate. 6. Metadata, including item definitions, descriptions of edits and imputations, and

pointers to related items in other datasets in the system, will be available integrally

with the data. Estimates of sampling error/uncertainty or the ability to calculate such estimates will be provided within the datasets.

7. The system and its use will save money compared to the traditional publication program so that resources can be dedicated to educating users and potential users on

how to access and use the system to get the products they need.

94 GOVERNMENT INFORMATION QUARTERLY Vol. 14iNo. l/1997

8. Most transactions will include a fee for service-for file extracts, for printed sum-

maries, for CD-ROM summaries, for graphical summaries, and so forth. 9. Development of the dissemination system is linked with planning for decennial cen-

sus and continuous measurement processing. 10. Development of ideas and plans will make use of the work already done or under-

way as part of CENSAS, DAPS90, the 1990 census DPSS, the Internet efforts, the

reinvention lab on post-collection processing, continuous measurement, the CPS

data access system, the Governments Division work, SIPP On-Call, the Population

Division data dissemination system, and so forth. 11. Both internal and external experts will participate in defining and developing this

system.

The Census Bureau summarized the messages received from users during these consul-

tations. Users said they wanted DADS to provide the ability for users to:

l Define their own data products online; l Access data documentation online in real time via hypertext links; l Retrieve, display, order, fax, and/or download prepackaged products; and l Talk to a qualified human if all else fails.

In addition, users said DADS would have to meet these basic requirements:

l Be simple and intuitive to use; l Support print-on-demand; l Provide online help and online training; l Notify users about the size, cost, and time required to fulfill requests; l Provide access to all census datasets.

In essence, the Census Bureau has taken the foregoing points as basic design principles

for DADS. The Bureau has adopted what it calls “iterative prototyping.” DADS ultimately

is to roll out for operational public use in the year 2001 as the keystone data delivery vehi-

cle for the 2000 Decennial Census of Population and Housing. In the intervening years, be-

ginning with the fall of 1996, the Bureau will deliver and test successive prototypes, one

per year. Each new prototype is intended to incorporate lessons learned from the previous

year’s version, and each is to embody increasingly complex functionality and extend to

more databases. Each will also be available to a larger group of data users. Part of the challenge in creating DADS lies in the fact that the system aims to encompass

extremely large databases. The 1996 prototype, for example, will include only the public

use databases from the 1990 census of population and housing. These databases alone con-

sist of 150 gigabytes. The Bureau collects and publishes statistics on population, housing,

agriculture, governments, business, manufacturing, and foreign trade, to name but a few of

its subject areas. The ambition for DADS is that the user will be able to tap into all those

statistical data areas online in real time. For the present the DADS design calls only for be-

ginning with the year 1990 and moving forward in time; that is, the system will omit his-

torical data prior to 1990. Nonetheless, the sheer size of the databases to be included will


pose substantial problems in information retrieval and data processing both from the stand-

point of system design and of data use.

POLICY ISSUES

In its work thus far on DADS, the Census Bureau has identified a set of policy issues that

it must investigate and resolve as annual DADS prototypes are developed and tested. The

Bureau does not yet have answers to the questions these issues pose, and finding workable

answers will be part of the development process. The list of policy issues is as follows:

Pricing/Cost Recovery; Minority and Rural Access; Metadata; Disclosure Avoidance; Data Integrity; Data Archiving and Preservation; Security; and Partnerships.

By way of a beginning, it will be useful to characterize the present state of the Bureau’s

thinking on three of these issues: Pricing/Cost Recovery, Partnerships, and Metadata.

Pricing/Cost Recovery

Whereas many agencies make use of the services of the National Technical Information

Service (NTIS) for selling their electronic information products, Census has always han-

dled such sales itself. Indeed, Census’s catalog of electronic information products is so

large that NTIS probably could not accommodate the volume anyway. Traditionally, the

Census Bureau has adhered to a policy of charging cost of reproduction and distribution for

these information products. However, in 1995, the Congress made clear that it wanted the

Bureau to charge more for its products. Accordingly, in April 1996, the Bureau announced

a new pricing policy that is reproduced below:

It is the policy of the Department of Commerce and the Census Bureau to make reasonable and equitable charges for services consistent with program and legislative requirements. This document outlines the Census Bureau’s policy on user charges for various products and services. Its purpose is to establish guidelines so that, to the extent possible, the Census Bureau will implement this policy in a consistent manner.

1. Certain products and services should be provided for free to the public. These may be

data samples, catalogs, order forms, or other products, such as Statistical Briefs, de-

signed for free dissemination to provide basic data to the public or to engage the pub-

lic’s interest in the products and services of the Census Bureau. 2. All other products and services of the Census Bureau will be provided on a fee basis

and will be priced. There are certain circumstances under which this pricing policy

may be waived based on program need or public good, on a case-by-case basis.

96 GOVERNMENT INFORMATION QUARTERLY Vol. 14/No. l/1997

Specific instances where fees may be waived are:

l Requests from the White House. l Requests from members of congress or their staffs for use in discharging the duties of

their positions. Constituent requests are handled on a fee basis. l Requests from other federal agencies where total fees would be less than $100 or more. l Requests from the news media. Beyond press releases, additional associated materials

may be provided at the discretion of the [Census Bureau] division chief. Other requests

from the media should be handled on a fee basis. l Requests for modest amounts of information to be photocopied, faxed or read over the

telephone. There should be a charge for photocopying or faxing 10 pages or more. An-

alysts should offer to fax or photocopy reports or printouts for a fee, rather than engage

in lengthy telephone discussions.

3. Prices, which will be reviewed annually, should reflect the full cost of dissemination,

including the costs of special preparation requirements. Given rapidly changing tech-

nology, this pricing policy will be reviewed periodically and updated as necessary. 4. This policy should apply equally to all media of dissemination, without regard to pro-

gram area or content.

CenStats: Internet Subscription Service

Within the Internet environment, the Census Bureau began implementing its new pricing

policy with an announcement, on June 20, 1996, of a new Internet subscription service

called “CenStats.” CenStats, which is available at [http://www.census.gov/prod/www& includes electronic copies of all reports published since January 1996 and selected reports

before that date. The Bureau stresses that large amounts of its data will continue to be of-

fered free over the Internet, but CenStats will also charge a fee for full copies of various re-

ports and data products now sold on CD-ROM;

Additional value-added features for CenStats are envisioned in the future. These include

the ability to download a single table, enhance data manipulation, and use extraction and

display tools, similar to some of the current features of the Census Bureau’s Internet site.

Ultimately, as part of the dissemination plans of the 2000 Decennial Census, users will

have the ability to design and print customized tables, charts, maps, and so forth using cen-

sus results. There will be a fee for such customized services, but the delivery time will go

from weeks to hours.5

Much of the pricing for DADS products remains still to be worked out. The Census Bu-

reau will use its experience with CenStats as a pilot for determining pricing algorithms for

DADS.

Partnerships

The Census Bureau expects that DADS will encompass various kinds of partnership ar-

rangements with other organizations. They are exploring many partnership possibilities as they develop DADS, including university centers, depository libraries, State Data Centers,

and other federal agencies such as the National Archives and Records Administration and

the Government Printing Office.


In a wider programatic context that includes but also goes beyond DADS, the Census Bureau is also exploring cooperative research and development agreements. In June 1996, the Bureau issued a notice in the Commerce Business Daily from which the following ex- cerpts are taken:

COOPERATIVE RESEARCH AND DEVELOPMENT AGREEMENT (CRADA)

The U.S. Census Bureau maintains the Nation’s largest and most complete databases con- cerning the country’s population and businesses. This information, when disseminated using the latest available technologies and marketing systems, would be of invaluable benefit to the Nation’s business, academic, and public sector communities. The Bureau would like to work in partnership with the private sector to conduct joint research, using both available Bureau technology and non-Federal expertise, to develop new data products and improve dissemination of this important data. Accordingly, CASIC, the Census Bureau’s Reinven- tion Laboratory [part of the National Performance Review spearheaded by Vice President Gore] invites proposals from interested parties regarding the possibility of entering into a CRADA to research, develop and market new products, within the parameters of the Bu- reau’s confidentiality protection requirements. The basic premise for these initiatives will be to develop new value-added data products useful for users’ market analysis, modeling and/or other business planning purposes. Subjects of research for possible CRADAs include, but are not limited to, the following:

1. Combining two or more existing Census Bureau datasets (e.g., economic, demographic and/or geographic).

2. Combining privately-developed software and/or datasets and Census Bureau datasets. 3. Combining Census Bureau datasets and those of other federal agencies, as permitted. 4. Combination of any of the above.6

CRADAs have their statutory basis in the Federal Technology Transfer Act (Title 15 United States Code, Part 37 10 et seq.). This law authorizes government laboratories to en- ter into agreements with private parties to conduct joint research. The government laboratory is allowed to provide, with or without reimbursement, personnel, services, facilities, equipment, intellectual property, or other resources, but notfunds. The private sector entity may provide funds, personnel services, facilities, equipment, intellectual property, or other resources toward the conduct of specific research or development efforts. The concept of joint research is a key element of CRADAs, that is, the collaborative nature of the relation- ship and the fact that it is a research activity.

Another particularly noteworthy feature is how intellectual property issues are treated under CRADAs:

To summarize, the CRADA’s ability to protect the jointly-produced data products depends primarily on who produced the product. While works prepared by Government employees cannot be copyrighted in the U.S., works prepared primarily by private partners may be copyrightable. The statute provides that all confidential commercial data products produced under the CRADA, including those produced by Federal employees, may be with- held from release for up to 5 years. The Census Bureau expects that the Government will either retain or receive a license to use any product developed under a CRADA. The terms of this license, and other intellectual property issues, are subject to negotiation.’

While the Census Bureau may enjoy a license to use the CRADA products during the five- year period, the public will not. These terms seem to admit the possibility that information

98 GOVERNMENT INFORMATION QUARTERLY Vol. 14/No. Ii1997

products generated from a joint research effort of the Census Bureau and a private firm might remain, in some circumstances, under the sole control of the private firm for a period of five years. A private firm might gain five-year exclusive use of a CRADA-developed database. While this contingency is explicitly permitted under the Federal Technology Transfer Act, it runs contrary to federal information policy as expressed in OA4B Circular

No. A-130.* The Circular states that:

Agencies shall avoid establishing, or permitting others to establish on their behalf, exclusive, restricted, or other distribution arrangements that interfere with the availability of information dissemination products on a timely and equitable basis. (@a (7)(a))9

A CRADA appears to mean that any members of the public not a party to the CRADA might have to wait five years for access to the underlying data. Indeed, CRADAs are structured precisely so that the private sector parties will have this five-year advantage; it is intended as an incentive to the private sector parties to make CRADAs more attractive

to them. While CRADAs have been around for some years, they have seldom been employed in

the area of federal database products. Most of the CRADAs have involved agencies such as the Department of Defense, the Department of Energy, or the National Institute for Stan- dards and Technology in the Department of Commerce, and each of these agencies has written regulations governing their CRADAs. The focus of CRADAs has tended to be on products that can be patented, rather than copyrighted. They have been used extensively for development of information technology hardware and software, but not for databases. Indeed, in inviting CRADA proposals the Census Bureau is venturing into terra incognita,

because the Bureau has no previous experience with this kind of legal instrument and has

not yet written regulations governing CRADAs.

Metadata

The DADS enterprise contemplates bringing all Census Bureau data together under a

single access system. The fact is that Census, like many other government agencies, oper- ates as a “stovepipe” organization, meaning that each group responsible for a particular subject area or set of statistical surveys works independently. The upshot is that the various subjects areas lack a common user interface, have poor interconnectivity, display dissimi- lar or inconsistent functions, cannot easily be interlinked, and lack common terminology and concepts. When one attempts to bring all these areas into a single system, one encoun- ters much duplication and overlapping of effort and many conflicts and inconsistencies from one dataset to the next.

On the other hand, the Bureau’s own studies of data users show that users usually do not behave in stovepipe fashion. Users frequently wish to cross over several subject areas; for example, users want to look at a variety of statistics for a particular geographic area. Creating DADS will require the development of metadata standards and common software tools.”

The term “statistical metadata” means descriptive information or documentation about statistical data that facilitates sharing, querying, and understanding of statistical data over the data’s lifetime. A “statistical information system (SIS),” as the Census Bureau now uses the term, means an online system that allows for the following:


l Statistical data access and retrieval; l Statistical metadata queries; l Mathematical and graphical summarization of data; l Navigation across concepts for locating information; l Graphical user interface driven access; and l Access to survey design documentation.

The principal features of a statistical information system such as DADS are that it will

encompass the following elements: l Statistical data database; l Metadata repository; l Survey documentation document library; l User interface; l Data manipulation and analysis tool set; l Metadata/documentation creation and update tools; l Feature interconnection infrastructure; l Interface for access with other information systems; and l Security matrix to protect confidential information.

In designing the SIS for DADS the Census Bureau will make the system compatible with Internet software; will use software adhering to national or international standards such as SQL (Structured Query Language) and IRDS (Information Resource Dictionary Sys- tem);’ ’ will adhere to metadata standards; and will apply architectural principles. The Cen- sus Bureau is now developing a statistical metadata standard called the Standard for Survey Design and Statistical Data Metadata (SDSM). ‘* SDSM is itself conceived as an extension to the Cultural and Demographic Data Metadata (CDDM) developed by the Federal Geo- graphic Data Committee.13 DADS will also adhere to the standard prepared for the Gov- ernment Information Locator Service (GILS).

CONCLUSION

The purpose of this article has been to alert information professionals to the fact that the U.S. Bureau of the Census is now embarked on the design of an ambitious, Intemet- based information dissemination system, DADS, that will determine how future information users gain access to data from this important information producing agency. The system is currently in the early stages of an annual prototyping exercise that will culminate with the release of data from the 2000 Decennial Census in 2001. The Cen- sus Bureau is aggressively seeking user feedback on its system design activities. Hence, the opportunity exists for data users to make their voices heard about how DADS will affect their interests.

The easiest way to follow DADS developments is by monitoring the Census Bureau’s web page at [http://www.census.gov]. Interested persons may also contact Marketing Ser- vices Office, Bureau of the Census, Department of Commerce, Washington, D.C. 20233. Telephone: 301-457-2902 [email protected]>.

100 GOVERNMENT INFORMATION QUARTERLY Vol. 14iNo. l/l 997

NOTES

1. U.S. Bureau of the Census, “Census Bureau Expands Electronic Data Dissemination,” press release, Wash-

ington, D.C., July 21, 1995.

2. U.S. House of Representatives, Committee on Appropriations for Departments of Commerce, Justice, and

State, the Judiciary and Related Agencies, 103rd Congress, Report No. 103-309, July 11, 1994, pp. 8 l-82.

The report states the congressional expectation that the Census Bureau would achieve $4 million from “data

sales” during FY 1995. In 1995, Congress raised the figure to $10 million for FY 1996.

3. U.S. Bureau of the Census, “Data Access and Dissemination-Guiding Principles,” Available at <http:// www.census.gov/rtp/pub/ dads/www/principles.html>.

4. Disclosure protection or disclosure avoidance refers to the set of statistical techniques used to ensure that

users of a database cannot identify individual persons whose characteristics are aggregated within the data-

base (and thereby defeat Census’s confidentiality safeguards). For example, if the value of a cell in a table is

some small number such that users could probably deduce the identity of persons with characteristics repre-

sented by that cell, a typical disclosure avoidance technique would be to delete the cell altogether.

5. U.S. Bureau of the Census, “Census Bureau Announces New Internet Subscription Service,” press release,

dated June 20, 1996.

6. U.S. Bureau of the Census, “Cooperative Research and Development Agreement (CRADA),” Commerce

Business Daily June 19, 1996.

7. U.S. Bureau of the Census, “Census Bureau CRADA: Background Information for Interested Parties,” press

release by U.S. Bureau of the Census, June 1996.

8. See J. Timothy Sprehe, “Does the Federal Government Need an A-130 for STI?,” Government Information

Quarterly, 12(1995), pp. 217-218, for a general discussion of this point.

9. Office of Management and Budget, Matmgement of Federal Information Resources, OMB Circular No. A-

130, Federal Register (February 20, 1996), p. 6433.

10. Daniel W. Gillman, Martin V. Appel, and William P. LaPlant, Jr., “Design Principles for a Unified Statistical

DatalMetadata System,” U.S. Bureau of the Census, Washington, D.C., paper presented at the Eighth Inter-

national Conference on Scientific and Statistical Database Management, Stockholm, Sweden. June 18-20,

1996. 11. National Institute for Standards and Technology, “Information Resource Dictionary System (IRDS),” Fed-

eral Information Processing Standards (FIPS) Publication 156 (April 5, 1989).

12. William P LaPlant, Jr., ed., “Standard for Survey Design and Statistical Methods Metadata,” internal Cen-

sus Bureau memorandum, U.S. Bureau of the Census, Washington, D.C. (1996).

13. Federal Geographic Data Committee, Subcommittee on Cultural and Demographic Data, “Cultural and

Demographic Data Metadata,” draft, September 15, 1994.

Documents

The U.S. Census Bureau's Data Access and Dissemination System (DADS)