Data element and metadata

Metadata: data describing other data (data about other data)

Metadata is data about data. In some cases, it does not specifically refer to a single piece of data. It can be understood as a group of information groups / data groups used to describe the data. All data and information in the information group / data group , All describe / reflect certain aspects of a certain data, then this information group / data group can be called a metadata.

Metadata can describe the elements or attributes (name, size, data type, etc.) of the data, or its structure (length, fields, data columns), or its related data (where, how to contact, owner).

In daily life, metadata is everywhere. As long as there is one type of thing, a set of metadata can be defined.

For example: you can find information about each movie on the movie database IMDB. IMDB itself also defines a set of metadata used to describe each movie. The following is its first-level metadata, and the second-level metadata is listed below each level. Together, they can describe a movie from more than 100 aspects:

Cast and Crew, Company Credits, Basic Data, Plot & Quotes, Fun Stuff, Links to Other Sites, Box Office and Business (Box Office and Business Development), Technical Info (Technical Information), Literature (Written Content), Other Data (Other Information).

The biggest advantage of metadata is that it enables the description and classification of information to be structured, thus creating the possibility of machine processing.

Data element: can be understood as the basic unit of data

The basic data element of health information standardizes and defines the unique Chinese name and code of all relevant information in the field of medicine and health, and the code is expressed in the form of letters, Chinese characters, and digital strings.

The data element lists and defines an information resource in a specific semantic environment.

Complete data element name = object class term + feature class term + representation class term + (limited class term)

among them:

A data element has one and only one object class term (object class) : It is a collection of things in the real world or abstract concepts, with clear boundaries and meanings, and can be identified because its characteristics and behavior follow the same rules.

A data element has only one characteristic class term (property) : It is a certain property shared by all individuals of the object class, and it is also the basis for the object to be distinguished from other members. It is a means for distinguishing and identifying things. Feature terminology is a necessary component of any data element name. In the case of a complete, accurate and unambiguous expression of the data element concept, other terms can be simplified as appropriate.

A data element has one and only one representation term (representation) : it is a combination of range, data type and representation, and also includes information such as measurement units and character sets. When there are repetitions or partial repetitions of the expression term and the feature term, the redundant word can be deleted from the name.

The restricted terms are given by the professional field, and the restricted terms are optional.

Basic model of data element

Differences and connections between data elements and metadata

Metadata cannot cover all the information necessary to understand the data to be represented by the data element.
Information about data elements is an integral part of any (organized) metadata.
Each element of metadata is a data element, and metadata is described with metadata attributes and description methods that conform to the data element standard.
Storing metadata in a library and making it organized requires modeling. Modeling requires obtaining metadata from the registration system or library of data elements.
Metadata is a data element expressed in a consistent and standard way.
Metadata and data element dictionary formats are composed of line number, Chinese name, English name, identifier (phrase), definition, constraints / conditions, maximum number of occurrences, data type, data value range and other attributes. The difference is that there are other attributes such as context and synonym name in the data element dictionary format.

In short, the definition of metadata and data elements are discussed from different angles. Due to the different emphasis of the description, the description attributes of metadata and data elements are also somewhat different, but the dictionary format of metadata and data elements is basically the same.

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. 1 metadata ( the Metadata )

1.1 Metadata concepts

1. Mainly describe the information of the data property (property);

2. Data describing the data;

3. Structured data about the data;

4. Describe the content, coverage, quality, management method, data owner, and data provision method of the data, which is the bridge between the data and the data user.

Examples:

The student information form includes: name, gender, student number, etc.

Name, gender, and student number are all data elements, but these data elements have their own metadata, that is, description data, which are length, type, and value range, respectively.

For the student information table, the name, gender, and student number are the data describing the student information and its metadata.

Data is a suitcase, and metadata is the sign on it.

Data is a folder, and metadata is a label above the folder.

1.2 The role of metadata

1. Data description: The ability to describe the content attributes of information objects is the most basic function of metadata.

2. Data retrieval: Support users' ability to discover resources, that is, use metadata to better organize information objects and establish their relationships to provide users with a multi-level and multi-path retrieval system, which is conducive to users to quickly and easily discover their true Information resources needed.

3. Data selection: Support users to have a basic understanding and knowledge of information objects without having to browse the information objects themselves to decide on the choice of detected information.

4. Data positioning: provide information about the location of the information resource itself, such as DOI, URL, URN and other information, so that the location of the information object can be accurately known, which is convenient for information acquisition.

5. Data management: Relevant information rights management such as processing and archival structure use management to save information resources, copyright, ownership, use rights, anti-counterfeiting measures, electronic watermarks, electronic signatures, etc.

6. Data evaluation: save relevant information of resources used and evaluated, through the analysis of the use of these information, it is convenient for the establishment of resources and managers to better organize resources and to a certain extent help users determine that the information resources are in the same kind of resources Importance.

2 Data element

2.1 Data element concept

1. Use a set of attributes to describe the data units that define, identify, represent, and allow values.

2. Also known as data type, a data unit described by a series of attributes such as definition, identification, representation, and allowable values. It is regarded as the smallest unit of data that cannot be divided in a specific semantic environment.

3. The data element generally consists of three parts: objects, characteristics, representation

Examples:

"Practice category code" is the data element, and "01" is the value of the data element.

In the "practice category code", "practice" is the target word, "category" is the characteristic word of the data element, and "code" is the expression word of the data element.

2.2 The role of data elements

1. The data element itself is also a data unit, that is, data.

2. It is a method or set of guiding theories used to normalize the data of various industries.

3. Use this set of methods to unify the name, type, value specification and classification of industry data.

4. After planning the industry data elements, it can lay the foundation for the industry to build a unified, integrated and stable data model, and it also lays the foundation for data exchange.

3 metadata management

3.1 Construction goals of metadata management