Metadata definition

In the last few years metadata has become a hot topic with new schemes and ideas to promote the interchangeability of ESMs or modelling components as well as data. The PRISM Metadata PAE provides a fomm to discuss, develop, and coordinate metadata issues with other national and international projects. The fundamental objective is to develop, document, and disseminate ESM metadata schemes as well as tools for producing, checking and displaying metadata. Currently, this PAE offers an opportunity to ensure coherence between the following metadata definition efforts ... 

Case Report Tabulation Data Definition Specification (Define.xml). Define.xml is the upcoming replacement for the data definition file (define.pdf) sent to the FDA with electronic submissions. Define.xml is based on the CDISC ODM model and is intended to provide a machine-readable version of define.pdf. Because define.xml is machine readable, the metadata about the submission data sets can be easily read by computer applications. This allows the FDA to work more easily with the data submitted to it. 

Currently, the included metadata are used to create additional functionality for the reader within an enhanced HTML view of an article. The ontology terms link to pop-up pages with the ontology definitions, further links, and related articles, whereas the compounds bring up a pop-up containing a two-dimensional structure, the InChl, and SMILES strings for the compound, names, synonyms, and related articles. This is best shown in Figure 8.1. 

It is important to preserve or translate as much of the original form and format of the data as possible, and that includes metadata. A database can contain a tremendous amount of metadata, such as audit trail information, electronic signatures, relationships between database tables, definition of field characteristics, etc. It is necessary to consider this metadata as part of the data set failure to do so could inhibit searchability and reporting after migration, make modification of old records problematic, or possibly even result in loss of the integrity of the records. Validation tasks associated with data migration must be geared to demonstrate that neither of these circumstances prevails. 

From time to time it may be necessary to remove data or other electronic records from an on-line computer system to another durable secure location for long term off-line storage. This removal also includes the removal of the metadata associated with the record, for example, the properties of a Microsoft Word document or a series of data definition and table relationships. 

Given the current desire of management to be able to mine data and see trends across studies and the availability of PK/PD repository systems (which we discuss more fully later), the first and foremost operating procedure requirement in pharmacometrics is the definition of key metadata that describes the process flow. Metadata, from the information science perspective, is simply information that describes data that is, where the data goes, what the data is, and what possible... 

Defining metadata on the file type level and storing them together with the file type definition. 

If metadata are predefined for a workspace or on file-type level, the user is prompted for entering missing metadata, either entered manually or via selection from a pick list. Predefined pick lists help to avoid misspellings, multiple ambiguous definitions. 

A solution is the definition of dependencies between metadata, which has consequences on the input of metadata if an object is created or uploaded. If a value is selected from the pick list for any metadata defined as primary data, available values for the secondary metadata are modified — usually reduced — according to the definition of dependencies. If only a single value remains to be valid for secondary data, the corresponding value is automatically selected. 

SRS uses metadata to define a class for a database entry object and uses rules for text-parsing methods, which are coupled with database entry attributes. For object definitions and recursive text-parsing rules, SRS uses its own scripting language called Icarus. For library specification and organization and for the representation of individual data fields within a system, SRS uses a Object Design and Definition (ODD) language. 

Different types of outliers need to be treated in different ways. Outliers that have occurred as a result of human error may be detected by consistency checks (or integrity constraints). If outliers are a result of human ignorance, this may be handled by including information on changing definitions as metadata, which should be consulted when outlier tests are being carried out. Outliers of distribution are usually detected by outlier tests which are based on the deviation between the candidate observation and the average of all the data values. 

The generic procedure of setting-up a collaboration hub is shown in Fig. 18.6. It is subdivided into 8 consecutive steps and starts with import of basic data and metadata, followed with definition of project template for access and selection of data. In the following steps collector mechanisms are activated, the different user access rights are set, and simulation of data import is conducted. Furthermore, it encompasses the major changes which may occur in project (update of project, change of project), and, finally, the project end or cancellation. 

Some data consist of single numbers only. Examples are critical constants and temperature and pressure for three phase equilibria of pure substances (triple points). Some kinds of data are single numbers by definition, such as normal boiling temperatures and standard enthalpies of formation at 298.15 K. Other data are functions of one or more independent variables. In general, the number of independent variables for a system is determined by the Gibbs phase rule. The database structure must allow for the maintenance of information on the phase or phases present, any constraints and other essential metadata, as discussed below. The distinction between a property and the... 

An HTML document (with the exception of frame set definition files) is structured into two parts. The first part is a header, which contains a title, metadata information, expiration dates, and other administrative information followed by a body, which contains the data displayed in the browser window. 

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