Nova Scotia's
    Geographic Information
    Standards

10.0 Introduction

A database directory and/or catalogue provides information to help consumers seek and locate information systems (electronic and hardcopy) containing specific data items. A directory is assumed to provide three primary services (taken from "Guidelines for International Interoperable Catalogue System", April 1993):

Cataloguing Service - provides descriptions of metadata or data set catalogues containing high level information suitable for making an initial determination of the potential usefulness of a data set for some application. Information on the location of metadata or data set catalogues will be found in the catalogue.

Guide Service - Provides detailed informaiton concerning specific data sets which enable the user to make a detailed analysis of whether a data set or a specific granule within the data set will be of value for some application. May also contain information necessary for analysis of the data (e.g. calibration coefficients).

Inventory Service - The inventory contains information needed to identify and retrieve the individual granule(s) of the data set, given the specification of the independent variable range(s); may contain information extracted from the data set granules as well as information to enable ordering.

The information contained within this chapter outlines the constructs for the creation of a database catalogue for the Province of Nova Scotia, including a questionnaire which will be implemented to collect information for a database catalogue and a description of the elements of that questionnaire, thus giving a database administrator a better understanding of the exact types of information required to populate the database catalogue Endnote 1 .

The Nova Scotia Catalogue of Geographic Information is a database of data sets for the Province of Nova Scotia. This catalogue will outline for the geomatics community of Nova Scotia, the corporate data sets which are available for access. In an effort to create this catalogue it is necessary to have the administrators of each of the corporate data sets complete a questionnaire describing the data sets. The results of the questionnaire will be the input data for the catalogue. As you complete this form (for each data set), please keep in mind that the information you provide provides three levels of service:

Cataloguing Service - provides descriptions of metadata or data set catalogues containing high level information suitable for making an initial determination of the potential usefulness of a data set for some application. Information on the location of metadata or data set catalogues will be found in the catalogue.

Guide Service - Provides detailed informaiton concerning specific data sets which enable the user to make a detailed analysis of whether a data set or a specific granule within the data set will be of value for some application. May also contain information necessary for analysis of the data (e.g. calibration coefficients).

Inventory Service - The inventory contains information needed to identify and retrieve the individual granule(s) of the data set, given the specification of the independent variable range(s); may contain information extracted from the data set granules as well as information to enable ordering.

So as to make completion of this questionnaire as easy as possible, the questionnaire is being presented as three seperate sections. Section One is a general section and it is requested that all participants complete this section. Sections Two and Three are directed at specific data sets, digital and hardcopy respectively. If the data set being documented is primarily a digital product, please complete Section Two, otherwise section Three is the more appropriate section to be completed.

If there are any questions regarding specific sections of the questionnaire, please consult the descriptive material below. If additional clarification is required, please do not hesitate to call the Land Information Services office at (902) 424-3761.

The following hierarchy of terms are offered to assist in dispelling some of the confusion regarding terminology. These terms are arranged in a hierarchical order from most general to most detailed descriptions of data sets. These terms are also presented in the "Geographic Information Nova Scotia - Standards Manual" - Appendix A: Glossary of Terms and Terminology.

Database Directory: A subset of a database catalogue comprising more than one and less than all fields found in the database catalogue.

Database Catalogue:A detailed description of all databases within the provincial land information system.

Data Dictionary: A repository of information about the definition, structure, and usage of data. It does not contain the actual data.

1 Title of Data Set Endnote 2
This section will highlight the common name(s) and acronym(s) referring to a data set.

1.1 Data Set Name
Please indicate the precise name referring to the data set.

1.2 Acronym(if any)
If an acronym is commonly used in referencing the data set please supply it, if not leave this section blank.

1.3 Previous Name(s)
In some instances a data set may have gone through a series of changes and/or modifications. In such cases the previous versions of the data set may have been referred to by another name.

2 Owner
This section will highlight the agency responsible for the data set being described. This is not a section for indicating a contact person for data set enquiries.

2.1 Department, agency, business, community university, etc.
Please supply the full name of the organization responsible for the data set.

2.2 Organization (check one)
While the precise name of the organization may clearly state the type of organization, for clarity please check one of the supplied types.

3 Contact Person
This section will highlight the most appropriate individual to be contacted when questions arise regarding the data set. Such a contact may be a database administrator, secretary, librarian, etc. Many of the items listed under this section are straight forward and will not be described here.

Organization
In cases where the contact person is found within a division or section of an organization, please indicate the name of the agency and associated section. (For example, Department of Municipal Affairs, Land Information Management Services Division) If acronyms are used please supply a definition of same.

4 Information on Data Set Content
This section allows for the opportunity to describe aspects of the data set, from the perspective of the administering agency.

4.1 Description of the data set
Only a brief summary of the main features of the data set is necessary.

4.2.1 Indicate Primary Keywords which might be used to reference this Data Set.
There is a List of Primary keywords supplied which you are asked to reference. Please ensure that you check at least on of the boxes supplied.

4.2.2 Indicate Secondary Keywords which might be used to reference this Data Set.
Please indicate other keywords which describe the data set. When selecting these secondary keywords to describe the data set ask the following simple question "What types of words would the average person use to reference this data set?" It is recommended that you supply no more than 6 secondary keywords. If however, others are warranted, please supply any and all of them.

4.3 Purpose / Use of the Data Set
Please state the primary intent of the data set. A data set may also have multiple intended uses. In such instances supply a general statement and give some examples.

4.4 Is this part of a larger data set or linked to other data sets (if yes, please indicate linked data sets)
In many instances a data set may not be all inclusive, such that some of its data may come from other data sets via a link. In other instances the data set being described may belong to a bigger data set. Please indicate if such is the case and in instances where links are formed please list the other data sets which are being linked.

4.5 Is this data set being collected as part of relevant legislation (if yes, please explain)
In some cases a data set may be closely tied to a piece of provincial legislation. For example a piece of legislation may dictate that certain information be collected or the resulting data set may have initiated a particular piece of legislation to be enacted. Supplying such information will allow the catalogue user to be alerted to other reference material (in this case legislation)

4.6 Language of data set
Indicate the official language in which the data set is supplied.

5 Geographic Coverage of Data Set
This section allows the opportunity to reference the data set to the ground.

5.1 Identify the area(s) covered by the data set
There are a number of possible options here.
Provincial Coverage - Is the data set related to a number of different areas covering a major portion of the Province?
Jurisdictional Unit - Is the data set confined to a particular jurisdiction, for example a municipal unit, electorial district, etc. Please specify the jurisdictional unit relating to the data set.
Map Sheet Name(s)/Number(s)(where applicable) - If the data set is confined to particular map sheets (i.e. less than 10) please supply a list of the map sheets. If however it was indicated that the data set is related to provincial coverage, do not list all map sheets.
Bounding Rectangle Endnote 3 (if different from complete map sheet coverage) - please supply the coordinates for the Lower left and Upper right corners of the rectangle in question. Coordinates may be in any spatial reference system (please specify)
Other geographical descriptions/references - in some instances the data set may be better referenced by a user defined area(s). For example a data set may be related to a watershed, etc.
Note:A map depicting the entire Province has also been supplied at the end of this questionnaire. Please feel free to plot on this map (or supply your own) if you feel the graphic reference will help.

5.2 Is the areal coverage complete?
The question to be asked here is "For the coverage indicated above, does the data set contain all possible data attempting to be described?" If, for example, a data set covers a particular watershed, is the data set 100% complete with reference to that watershed, if not indicate No and supply a brief explanation as to why. Dynamic data sets will never be complete, therefore please check N/A.

6 Time Coverage of Data Set
This section should define the dates being covered by the data set.

6.1 Frequency of Updates to data set
Indicate how often the data set is updated.

6.2 Please identify the Time Period Covered by data set (CCYY/MM/DD) Endnote 4
Do not indicate the time at which the data set was populated, or updated. An example of what is to be supplied here would be if the data set is a historical one and covers an aspect of World War II, if such were the case, the Beginning and Ending dates would be the time period spanning World War II.

6.3 Is the time coverage complete?
In the WWII example, if the data set has a major gap in content, the answer here would be No and the explanation may relate to the actual gap in the data set. If the data set is dynamic the response here would be N/A.

6.4 Date of last data set update/revision (CCYY/MM/DD)
Indicate the date at which the content of the data set was last worked on (not the description of the data set). This is an indication of the currency of the data set. If for example on June 1994 an individual queries the catalogue and notes that the data set in question is updated monthly, but that the last update was done in March 1994, the individual would have a better appreciation of the data set's currency.

7 Details of Data Collection
This section will allow a person to gain a better understanding of how the data set was created.

7.1 Map Base Endnote 5 Used (if applicable)
Indicate the type of map used as a foundation for locating/referencing the data set's information. If you know that the map base you are using has been modified from an original, please indicate that your map base is a modified version (for example, perhaps your base is a 1:50 000 National Topographic System (NTS) map internal to your organization, which has had the index contours removed, your map base should be flagged as a modified version of the 1:50 000 original). If the data set is the map base itself please indicate with N/A.

7.2 Period during which data was collected (CCYY/MM/DD)
The date(s) included here may differ from the dates indicated in the section above entitled "Time Coverage of Data Set". In the example given previously, Time Period covered may be WWII, the actual data set may not have been created until sometime in 1993. This would be the date to include here. Such information may allow the user of the catalogue to appreciate some of the possible technologies used to create the data set.

7.3 Source(s) of the data
Indicate how the data set may have been gathered. Note: Survey and Survey Plans refer to actual use of Survey Engineering techniques, not field surveys or windshield surveys.

7.4 Details associated with data collection....
In some instances the data set may have been generated via conversion of other information, in such cases please indicate with a brief description. As well, if the data set in not uniformly representative Endnote 6 of the information being portrayed please state limitations.

7.5 Map Projection
Indicate the map projection used to depict the information contained in the data set.

7.6 Coordinate System(s)
Indicate the coordinate system(s) used to reference the data within the data set.

7.7 Geodetic Datum
Indicate the horizontal and vertical datums used to reference the data set.

7.8 Scale or resolution at which the information was
Collected - This will give some indication of the accuracy of the data.
Entered into data set - If the same as above please indicate anyway. Again it will allow the user to better appreciate the accuracy of the data.
Pixel Resolution - in the case of raster data, pixel resolution information will give a sense of data generalization.

7.9 Positional Accuracy
This question should only be answered if the accuracy and resolution are known and published, or if a reasonable estimate based on sound technical knowledge is available. Absolute positional accuracy is an estimate of the error in the location of features in the data set with respect to published geodetic control coordinates or elevation for a specific geodetic datum. If there are cases where other accuracies are more relevant to the user of the data, for example confidence intervals, percentages, etc., use the "Other accuracy" portion of the question.

8 Data Quality (and Accuracy)
Please supply comments regarding the quality of the data (including, where applicable, topological relationships) contained in the data set. Be brief. Examples include: "No Quality Control used in verifying data set"; "Data set has been collected as per the (insert name here) Data Quality Assurance Program"; "Only Network Topological Processing has been carried out on this data set". If there are instances where additional explanation is necessary, direct the user of the catalogue to get in touch with the "Contact Person".

9 Access Policy (product or distribution policy)
This section will give an indication to the catalogue user of any restrictions placed on the use of the described data set. Please indicate if the data set is for public access or has restricted access. In the cases where access is restricted please supply details. Based on the response to this question, special mechanisms may be put into place to restrict viewing to particular audiences.

Liability disclaimers
If there is a liability disclaimer associated with a data set, please supply the disclaimer. If no disclaimer exists simply insert N/A.

Copyright status
In some instances a copyright may be imposed on a data set. Please indicate appropriately.

10 Charges/Fees
This section will allow both government departments and general public to anticipate any costs which may be associated with access to a data set. If charges are yet to be determined or if there are no charges associated with access to a data set, please mark the appropriate section with an X.

11 Physical Access to Data Set
This section will allow the user of the catalogue to determine if direct access to a data set is possible. If a person wishes to gain access to a data set and no means of direct access is possible, please mark "No Direct Access Available"

12 Size of Data Set
This section gives the catalogue user an indication of how large a data set is. It is meant to be an indication of size in relation to digital data sets.

12.1 Size of data set (uncompressed)
Due to the various types of compression routines available, size details regarding compressed files do not give a potential user an indication of the true size or complexity of a data set. Uncompressed on the other hand will allow the user to better appreciate the data set. If the data set consists of a map series, please indicate the overall size of the data set. Indicate also if the size being specified is in kilobytes(Kb), megabytes(Mb) or gigabytes(Gb).

12.2 Number of Records Endnote 7
Indicate the number of records found in the data set. If the data set consists of a map series, please indicate the number of maps available in that series (for example the 1:250 000 federal map series for the province of Nova Scotia consists of 10 map sheets, therefore the number of records for the data set is 10).

12.3 Number of attributes/fields Endnote 8 per record
Indicate the number of fields identified for each record.

13 Data Set Media
This section will allow the user of the catalogue to gain an appreciation of the type of media on which the data set is available (hardcopy and/or digital) Be sure to check as many boxes as are applicable to the data set in question.

14 Host Computer
In instances where a data set is available in digital form, please indicate the type(s) of host computer(s) housing the data set.

15 Make and Model
Indicate the make and model of the host computer.

16 Operating System
Indicate the operating system being used on the host computer along with the version.

17 Software Systems Employed
There are many possible types of software employed for a given data set. Be sure to indicate all types of software which are employed to present the data set along with the software's version.

18 Data Structure
This section is concerned with how the graphic data elements are arranged within the data set. The basis for the file structure for graphics data only, is required. Some terms which may require clarification include:
Vector - a representation based on vector coordinates of graphic features.
Topological/Polygonal - a method of coding which enables the relationships among points, lines and areas to be explicitly described.
Raster - a regular grid of cells or a pattern of scanning lines used for producing images.
Quadtree - a system of stacked (recursively divided) grid cells of varying sizes.

19 Supporting Documentation
In this section please list all descriptive documentation which supports the data set being described. As well, indicate if a demonstration package or tutorial is available for the user.

20 Comments
In cases where there is information not covered by this questionnaire, which would help the user of the catalogue to better understand the data set, please supply any additional detail believed necessary.

21 This form was completed by
Please be sure to sign and date the bottom of the form.

Endnotes:

Endnote 1 - Historically the Province has been developing a Digital Index of Land Information (DILI). Prior to the creation of this standard, DILI was the defacto standard for metadata. After review, however, it was believed that to better serve the needs of the consumer, additional information needed to be included in DILI, thus the development of this standard. DILI will continue to evolve and will, in time, incorporate the materials included below.

Endnote 2 - A Data Set is defined as a collection of similar or related data having the same characteristics (source, processing level, resolution, etc.) but different independent variable ranges. A data set may be a digital or conventional database, it may be a series of table, charts, maps, etc., which have been geographically referenced.

Endnote 3 - Bounding Rectangle - A rectangle specified by coordinate pairs which defines a regular or irregular geographical area, by the minimum and maximum coordinates of a feature. A map sheet can be referred to as a bounding rectangle. A map inset can be defined as a bounding rectangle.

Endnote 4 - CCYY/MM/DD - format corresponds to the Information Technology Architecture standard's date formats as defined by the Department of Supply and Services. This format is to be used throughout the form whenever possible.

Endnote 5 - A map base can be any map graphic which has been used to reference information within the data set.

Endnote 6 - Uniformly Representative - An example of a data set being uniformly representative would be Bud Worm Infestation S/W Nova Scotia 1987-1993 where data were collected monthly and there were no gaps in data. If however this same data set has gaps in the data, it would no longer be uniform

Endnote 7 - Record - A collection of fields in a database, or a set of data elements which are treated as a unit, for example Name, Address and Telephone Number may make up one "Member" record in a Health Club data set.

Endnote 8 - Field - A piece of information in a record which helps describe that record. For example, Name, Address and Telephone Number are all fields found in the record "Member".

Standards Manual's Table of Contents