An Introduction to Meta Data

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An Introduction to Meta Data Powered By Docstoc
					   Introduction
        TO
    Metadata!
         Gary Johnson
Nevada Bureau of Mines & Geology
What we will talk about
 What metadata are?


 Metadata tools (ArcView extension)


 www.FGDC.com
What are METADATA?
 Metadata consist of information that characterizes data.
    Metadata are used to provide documentation for
    data products.
In essence, metadata answer:
        who
        what
        when
        where
        why
        how
about every facet of the data that are being
documented.
                            Nothing on the back
                               of this photo,
                            Who is in the photo?

Back of photos tell who is in the photo,
data of photo, where the photo was taken.
Nothing indicating who is in this photo
           Who Are they?
Metadata tells who, what, where and when:
Metadata placed on back of photo
Why should I create metadata?
  Metadata helps publicize and support the data you or
     your organization have produced.

  Metadata explains what you have done when you are no
     longer with the agency.
 Metadata that conform to the FGDC standard are the
 basic product of the National Geospatial Data
         Clearinghouse, a distributed online catalog
 of digital spatial data. This clearinghouse will allow
 people to understand diverse data products by
 describing them in a way that emphasizes aspects
 that are common among them.
Who should create metadata?
Data managers who are either technically-literate scientists
or scientifically-literate computer specialists.

Creating correct metadata is like library cataloging, except
the creator needs to know more of the scientific information
behind the data in order to properly document them.

Don't assume that every -ologist or -ographer needs to be
able to create proper metadata.

Ensure that there is good communication between the
metadata producer and the data producer; the former will
have to ask questions of the latter.
How do we deal with people who
complain that it's too hard?
The solution in most cases is to educate the creator of the
data to use an easy tool rather than to develop new tools.


 People often assume that data producers must generate
 their own metadata. Certainly they should provide
 informal, unstructured documentation, but they should
 not necessarily have to go through the rigors of fully-
 structured formal metadata.
The Real Question is:
 If I already know what metadata are, then
  what next?
  – To learn how to compile your metadata in a
    standard format.
     • Just like a recipe.
     • Just like a book is catalogued in the library.
     • Just like a step-by-step how-to instruction manual.
Why Can’t I Just Write Readme
Files?
 Readme files vary in the amount and quality
  of information they contain.

 You will be writing “readme” files, that are
  in a standardized format that can be
  searched on-line, and contain the kinds of
  information that we would all like to see in
  a “readme” file.
The “Standard”
 The Federal Geographic Data Committee
  (FGDC) was assigned the task of
  developing a “standardized documentation
  of data” through Executive Order 12906.
 What they came up with was the Content
  Standard for Digital Geospatial Metadata
  (CSDGM).
 www.fgdc.gov/metadata/contstan.html
Objective of the Standard
 To provide a common set of terminology
  and definitions for the documentation of
  geospatial data.

 Developed from the perspective of defining
  information required by a prospective user.
 Non Spatial Data vs. Spatial Data

 Non Spatial Data (in the form of a paper
  map) has a legend that displays the
  information (the metadata) about the map.

 Spatial Data has no legend, so a conscious
  effort is required to develop and maintain the
  information (metadata) that goes with the
  data.
 Information Required by a User

 Availability -- Does data exist for the
  geographic location I’m interested in?
 Fitness For Use -- Does the data meet my
  specific needs?
 Access -- How do I acquire a specific data
  set?
 Transfer -- How do I process & use the data?
Organization of the Standard (derived
from the FGDC’s CSGDM)

 Hierarchy of compound elements and data
  elements (sections, sub-sections, sub-sub-
  sections).
 Each compound element (section) is
  individually numbered and also contains
  compound elements (sub-sections) and data
  elements (sub-sub-sections).
Conventions for Dates (These dates use ANSI
X3.30-1985: New York, American National Standards Inst.)


 Calendar Dates (year, month, day)
  – YYYYMMDD
  – YYYY = year
  – YYYYMM = year and month
  – YYYYMMDD = year, month and day
Meta Data Resources:
 The web has a number of resources to learn
  more about meta data. A couple of places
  to start are:
 www.fgdc.gov (links to other sources,
  examples of meta data, meta data collection tools,
  and clearinghouse node).
 www.lic.wisc.edu/metadata/metaprim.htm
  (meta data primer).
 www.blm.gov/gis/metadata.html (Barney -
  The Meta data Hero! [a meta data tutorial]).

				
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