Transcript
Page 1: Database schema for representation of data and meta-data for a survey software system

82S Abstracts

P10 DATABASE SCHEMA FOR REPRESENTATION OF DATA AND

META-DATA FOR A SURVEY SOFTWARE SYSTEM

R o b e r t B. G o l d s t e i n , C h e r y l C a s w e l l , B r i a n S c h u t h a n d Foss Tighe New England Research Institutes

Watertown, Massachusetts

The database schema used to store the answers to complex surveys must satisfy many different and sometimes contradictory needs that cannot be simultaneously satisfied. The structure used must be able to: • represent multiple types of meta-data, including

- special values such as 'refused', 'don' t know', and 'unknown'; - date and time showing when data were collected or changed; - previous values (or an audit trail) for the answer in the event it was changed; and - free text information to store comments about the answer

• use (possibly via supplied conversion utilities) standard SQL for ad-hoc queries • be converted into analytic datasets ® represent longitudinal data and follow-up surveys • handle dates that are only partly known • be customizable and extensible so that each study may define special coding values and

unique required meta-data. Several alternative approaches were evaluated and balanced against the above criteria

including (a) inversion of the matrix making each answer a separate record; (b) binary coding of special values in a separate table that parallels the structure of the data table; (c) use of an 'escape' code such as a 'zero' or 'null ' that indicates the existence of important meta-data; (d) representation of special values using "out-of-range" numbers; and (e) variations of these schemes that use data dictionaries and shadow fields within the data table.

The results of these tests, including the positive and negative features of each scheme will be presented. The actual scheme chosen to be used within our Windows-based Computer Aided Telephone Interviewing software, WINCATI, will be shown and details of implementation presented.

P l l USING HARVARD GRAPHICS ® AND

AN HP DESIGNJET 650C/PS ® PLOTTER TO PRODUCE LARGE-FORMAT

RESEARCH POSTER PRESENTATIONS

M a z e n A b d e l l a t i f a n d L a r r y B r a n d

VA Cooperative Studies Program Coordinating ('enter and VA Health Services Research and Development

Hines, Illinois

Until two years ago, we designed our research poster presentations the traditional way. We printed contents on small pieces of paper, which we arranged and thumbtacked to a bulletin board with the aid of a ruler, scissors, and glue. Our Coordinating Center and Health Services Research and Development coordinate and conduct many large-scale clinical trials and health services studies that generate many presentations annually. Two years ago, our centers decided that it was time to employ the latest technology in constructing our poster presentations. We purchased an HP Design Jet 650C/PS ® color plotter and used it with Harvard Graphics ® , the officially supported graphical software at our centers, to generate our poster presentations. Since then, we generated dozens of these large-format posters that we presented at professional scientific meetings such as the Society for Clinical Trials. Their quality and professionalism impressed the participants of these meetings. In fact, most of

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