Social surveys provide us with rich information regarding the responses of people to various questions. Among a vast array of possible combinations of question items, the researcher generally focuses only on a particular set of items, whose analysis serve to meet the researcher's specific objective.

Alternative perspectives, however, necessitates researchers to focus on different combinations of questions for analyses. Traditionally, when secondary analyses of existing data were not possible, researchers have had to either collect his/her own data, or abandon the research plan.

By facilitating secondary analyses of deposited data, data archives promote multitudes of new research, that would otherwise have not been possible.

Social surveys are made possible through the extensive efforts of researchers and the generous cooperation of respondents. They are also extremely time-consuming and expensive. It is therefore strongly recommended that social survey data are utilized as effectively as possible.

Having to collect new data, because existing data are not accessible, entails not only the waste of time and money, but also the unnecessary imposition of research effort on the part of respondents, which may eventually undermine their support for social science research.

Effective use of existing data, in this light, is a responsibility that social scientists bear upon respondents of social surveys. Data archives, therefore, contribute to alleviating the burden placed upon survey respondents.

SSJDA was established as a unit within the Information Center for Social Science Research on Japan, Institute of Social Science, The University of Tokyo, in order to promote effective use of social survey data. It is unrealistic at this point, however, to assume that SSJDA alone can collect and maintain the vast archive of social science data. Hence, we encourage organizations and researchers to join us in our effort, by making data acquired in their specific professional fields available to the public. It is through such joint commitments that the overall quality of Japanese archival data can be improved.

Based on this understanding, SSJDA collects data from those organizations and researchers that are unable to distribute their data individually, but are willing to deposit them with us, while encouraging those that are able to. Additionally, in order to facilitate the data-users' task of locating relevant data from among multiple data archives, SSJDA provides a comprehensive index of data archives on the Internet, enabling data-users to establish necessary linkages. Upon approval from the data-owners, information on several datasets are provided directly from this index.

Given the increasing social concern about privacy issues in recent years, we fear that people may refrain from participating in social surveys, when they are informed that their responses will be archived and made publicly accessible. In preparing data for public release, SSJDA ensures that the identity of research subjects cannot be disclosed.

SSJDA also limits the use of its data to not-for-profit, academic research, and grants data access only to researchers and graduate/undergraduate students under the supervision of faculty members at academic institutions. Furthermore, SSJDA requires all data users to consent to the confidentiality agreement that the data shall not be analyzed in any way that will disclose the identity of individual respondents or organizations.

A successful secondary analyses requires full understanding of the social survey: its research design, definition of terms, data collection procedures, etc. Lack of understanding, therefore, risks misuse of the data which may lead to inadequate conclusions.

In order to prevent such misuse, SSJDA provides data-users with necessary information and instructions. A "Users Manual"is prepared for each dataset, and a collection of survey reports containing information on the datasets is offered to data-users for reference. We also welcome inquiries from data-users.