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Content Standard for

Computational Models



CSCM Version 1.0


Metadata for Models Work Group

Alexandria Digital Earth Prototype Project

University of California, Santa Barbara


Current draft as of:

May 21st 2001

Content Standard for Computational Models

(CSCM)


OBJECTIVES:

The objectives of the standard are to provide a common set of terminology and definitions for the documentation of computer models. The standard establishes the names of data elements and compound elements (groups of data elements) to be used for these purposes, the definitions of these compound elements and data elements, and information about the values that are to be provided for the data elements.

SCOPE:

In 1989, Science Magazine had an article titled “Is it real or is it Crazy?” (Pool, 1989) in which they were introducing a whole new field of science referred to as computer experimentation. At that time only a handful of laboratories across the globe had the “super computers” large enough; powerful enough to operate computer models.


Now, nearly 12 years later, computer models can be transferred “over the web” or “burned” onto a plastic disk, and downloaded into a palm-held computer. As technology continues, I’m sure that in the near future we’ll look back at today’s greatest technology as if were archaic.
This sudden boom in technology has been paralleled by a sudden influx of computer models into the scientific community. Models are being used for research and understanding of everything from Hydrology to Yarn manufacturing, from gold deposits to survival rates in ICU’s. With this sudden flux, comes a bit of confusion.
The problem that arises is that, to date, there has been no standard method for one person to communicate with another about the model that they have, and with this breakdown in communication, there lies a breakdown in the ease of sharing knowledge and experience. For this cause, a Computer Model Metadata Standard has been needed.

The driving force behind this effort to develop a computer model metadata standard is the increasing number of digital libraries, registries, and clearinghouses, and the need (and desire) to be able to catalog computer models in these sources. It is through these sources that the knowledge and experience gained in model technology can be shared and distributed.


The effort of creating a model metadata standard is taking place in the academic arena. The academic community has a vested interest in computer models. Not only are models used both in instruction and research, but also it is through said research that many models are developed. The academic circle will be able to develop standards that will be useful for academia, yet applicable and accepted to those both in government and industry.
TABLE OF CONTENTS:


Page


Overview………………………….……………….4

Compound Elements…………………..………...5

Properties of Data Elements…………………….5

METADATA STANDARD


Section 1: Identification Information…………………..8

Section 2: Intended Use.……………………………….9

Section 3: Description……………………………..……9

Section 4: Access or Availability…...………………...13

Section 5: System Requirements…………………....14

Section 6: Input Data Requirements..……………….15

Section 7: Data Processing…………………………...17

Section 8: Model Output………………………….…...17

Section 9: Calibration Efforts & Validation.……..…...19

Section 10: Metadata Source…………...….………...19


CODE LISTS


Code List 1: Application Purpose…...…………….21

Code List 2: Educational Level…………………....21

Code List 3: Conceptual Model Typology…..…....21

Code List 4: Topic of Field of Study….….….…….21

Code List 5: Planetary Bodies ...………….……….22

Code List 6: Access or Use Constraints…...….….22

Code List 7: Construct Classification……….……..22

APPENDIXES


A: Glossary…………………………………....23

B: References………………………...…..…..25

OVERVIEW:
1. Name of Standard. Content Standard for Computational Models.
2. Explanation. This standard specifies the information content of metadata for computer models. A computer model can be defined as software whose primary function is to model a certain class of physical systems, and may include pre- and post-processing components and other necessary ancillary programs (Dee, 1994). This is often referred to as computer modeling software.
The purpose of the standard is to provide a common set of terminology and definitions for concepts related to these metadata. Metadata are data about the content, quality, condition, and other characteristics of the specified model.
Work began on a computer model metadata standard for the purpose of incorporation of computer models into digital libraries (Specifically, the Alexandria Digital Library at the Univ. of California, at Santa Barbara.)
This draft is currently under public review.
3. Approving Authority. This documentation, as of May 2001, still awaits approval through academic circles.
4. Maintenance Authority. The current maintenance authority for the standard is the Metadata for Models Work Group, the Alexandria Digital Earth Prototype, U.C. Santa Barbara. Questions and comments concerning the standard are to be addressed to Scott Crosier: scott@geog.ucsb.edu.
5. Related Documents. No list of related documents exists as of May 2001.
6. Objectives. The objectives of the standard are to provide a common set of terminology and definitions for the documentation of computer models. The standard establishes the names of data elements and compound elements (groups of data elements) to be used for these purposes, the definitions of these compound elements and data elements, and information about the values that are to be provided for the data elements.
The major uses of metadata are:


  • to maintain an organization's internal investment in computer models,




  • to provide information about an organization's computer model holdings to model catalogues, clearinghouses, digital libraries, and brokerages,




  • to provide information needed to process computer models to be received through a transfer from an external source, and




  • to describe the input data and output data parameters and formats necessary for operating the model as well as hardware and software requirements for running the model

The information included in the standard was selected based on six roles that metadata play:




  • Identity – basic data required in order to identify the model.




  • Functionality – data needed to determine the intended function of the model.




  • Fitness for use – data needed to determine if a computer model meets a specific need.




  • Access – data needed to acquire an identified model.




  • Validation – data needed to determine the accreditation of a computer model.




  • Transfer – data and hardware needed to process and use a model.

The exact order in which data elements are evaluated, and the relative importance of data elements, will not be the same for all users.


7. Applicability. This standard is for the documentation of computer based models. Computational models refer to software whose function is to model a certain class of physical systems, and may include pre- and post-processing components and other ancillary programs.(Dee, 1994)
8. Specifications. The standard provides specifications for terminology of data elements and compound elements, definitions for this terminology, and information about values to be provided for the data elements.

Information about terms that are mandatory, mandatory under certain conditions (conditional), and optional (provided at the discretion of the data provider) is provided by the standard.


9. Where to Obtain Copies. Copies of this publication are available from Scott Crosier, UC Santa Barbara: scott@geog.ucsb.edu or downloadable in word.doc format from: www.geog.ucsb.edu~scott/standard/standard.doc


COMPOUND ELEMENTS

A compound element is a group of data elements and other compound elements. All compound elements are described by data elements, either directly or through intermediate compound elements. Compound elements represent higher-level concepts that cannot be represented by individual data elements.


PROPERTIES OF DATA ELEMENTS
DATA ELEMENT

A data element is a logically primitive item of data. The entry for a data element includes the name of the data element, a short name, the definition of the data element, the obligation requirements of the element, the maximum occurrence of the element, or repeatability, the data type and the domain of the element.


SHORT NAME

Each element and compound element is provided with a short name. These short names are unique within the standard and may be used with the Extensible Mark-Up Language (XML), Unified Modeling Language (UML) or other similar implementation techniques. A naming convention similar to that used to create the longer entity and element names was used.


NOTE: Implementation using Standard Generalized Markup Language (SGML) and Extensible Mark-Up Language (XML) is not mandatory; other implementation methods may be accommodated.
DEFINITION

Each Compound and Data Element is provided with a description.


OBLIGATION / CONDITION

A descriptor indicating whether a metadata entity or metadata element shall always be documented or sometimes be documented (i.e., contain value(s)). This descriptor may have the following values: M (mandatory), C (conditional), or O (optional).


Mandatory (M):

The metadata entity or metadata element shall be documented.


Conditional (C):

Specifies an electronically manageable condition under which at least one metadata entity or a metadata element is mandatory. ‘Conditional’ is used for one of the three following possibilities:



  • Expressing a choice between two or more options. At least one possible option or more is mandatory and must be documented.

  • Documenting a metadata entity or a metadata element if another element has been documented.

  • Documenting a metadata element if a specific value for another metadata element has been documented.

To facilitate reading by humans, the specific value is used in plain text. However, the code shall be used to verify the condition in an electronic user-interface.

If the answer to the condition is positive, then the metadata entity or the metadata element shall be mandatory.

The condition identifies also the metadata entity identifier or the metadata element identifier and the allowed value where appropriate, upon which the condition is formulated.


Optional (O):

The metadata entity or the metadata element may be documented or not documented. Optional metadata entities and optional metadata elements have been defined to provide for fully documented data.

(Use of this common set of defined elements will help promote interoperability among model users and producers world-wide.) If an optional entity is not used, the elements contained within that entity (including mandatory elements) will also not be used. Optional entities may have mandatory elements, those elements only become mandatory if the optional entity is used.
MAXIMUM OCCURENCE

Specifies the maximum number of instances the metadata entity or the metadata element may have. Single occurrences are shown by “1”; repeating occurrences are represented by “N”.


DATA TYPE

The information about the values for the data elements includes a description of the type of the value, and a description of the domain of the valid values. The type of the data element describes the kind of value to be provided. The choices are "integer" for integer numbers, "real" for real numbers, "text" for ASCII characters (including those characters relating to a URL address or an electronic mail address), "date" for day of the year, and "time" for time of the day. Where values are to be selected from a predetermined vocabulary or a code list provided with the standard, the data type is “class.”


DOMAIN

The domain describes valid values that can be assigned to the data element. The domain may specify a code list of valid values or restrictions on the range of values that can be assigned to a data element.


The domain also may note that the domain is free from restrictions, and any values that can be represented by the "type" of the data element can be assigned. These unrestricted domains are represented by the use of the word "free” followed by the type of the data element (that is, free text, free date, free real, free time, and free integer).

Some domains can be partly, but not completely, specified. To allow a producer to describe its model in these circumstances, the convention of providing as one of the options in a list of values being “other”. In the case where the option “other” is used, the following optional element allows the producer to specify the value and from which standardized list it was drawn.


CALENDER DATES (Years, Months, and Days)

Character encoding of a date is a string, which shall follow the format for date specified by ISO 8601 + extension proposed by OGC Web Mapping Testbed (Basic Service Model Draft). According to that standard, dates shall be recorded as follows: YYYY-MM-DD. Further information relating to ISO standard 8601 can be found at the following URL address:



http://www.iso.ch/markete/8601.pdf
MODEL vs. MODULE OF MODEL

If the metadata is in regards to a specific module of a model, this shall be so noted in the model title (line 2)


The following is the recommended bibliographic citation for this publication:
Alexandria Digital Earth Prototype, Metadata for Models Work Group. Content standards for computer model metadata. 2001
In the creation of this Metadata standard, the ISO TC 211 "Geographic Information Metadata Standard Committee Draft" (CD19115.3; 211N930) was used as a guide. The U.S. Federal Geographic Data Committee's "Content Standard for Digital Geospatial Metadata" has also provided guidance. As this Metadata for Models is further developed, a goal will be to harmonize it as much as possible with these and other metadata standards.
Element Definitions for Computational Model Metadata
Sec. 1: Identification Information


No.

Element Name

Short Name

Definition

Obligation / Condition

Max. Occurrence

Data Type

Domain

1

Identification Information

IdInfo

Basic identification information about the model

M

1

Compound

lines 2-7

2

Model Title

title

Selected and agreed upon name referring to the model, modeling package, or model instance.

M

1

Text

free text

3

Version of Model

version

Version of model for which the metadata documentation has been created.

C - Is there now or will there be more than one version?

1

Text

free text

4

Responsible Party of Model

respParty

Identification of, and means of communication with, person(s) and organization(s) associated with the model.

M

N

Compound

sec 1.1, lines 8-11

5

Date of Creation

createDate

Date that this version of the model was released.

M

1

Date

ISO 8601

6

Model Citation

citation

Recommended citation to the model established by the group or individual responsible for the model.

M

1

Text

free text

7

Model Identification Number

id

Any identification number associated with this model.

O

N

Text

free text
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