imt530- organization of information resources1 feedback lectures –more practical examples –like...

IMT530- Organization of Information Resources 1

Feedback

• Lectures– More practical examples– Like guest lecturers– Generally helpful in understanding concepts

• Readings– Too much and too dense sometimes, not clear what applies

specifically– Those in weekly reading group find it helps

• Group Work/Exercises– Helps clarify concepts, but not enough time in class

• Other– Still not clear on assignment– Want more management focus


Recap

• Descriptive metadata elements can be used for access or selection

• Users don’t know what’s in your information system unless you make it explicit

• Cutter’s Objects of the Catalog (modernized)– To enable a person to find an item where some

information about it is known– To show what the system has by a given entity on

a given subject in a given type of category– To assist in the choice of an item by specific

characteristics

Module 5a: Authority Control and Encoding Schemes

IMT530: Organization of Information Resources

Winter 2008

Michael Crandall


Module 5a Outline

• Metadata can be used in many ways• Why authority control?• Controlled vs. uncontrolled values• Principles of authority control• Examples of authority control in libraries• How does it work?• Why do it?• Some issues in authority control• Alternatives


Metadata can be Used Many Ways

• It should be obvious by now that metadata may be constructed for a particular purpose, but used in many ways– Descriptive metadata can be used for access– Administrative metadata can be used for

description– Structural metadata may be used for administration– All may be used for management or control– Users may need access through unexpected

pathways• Underscores importance of providing ways to

manage creation of metadata for consistency


Why Authority Control?

• In the library world, authority control is used to ensure that Cutter’s Objects are satisfied- all items can be brought together while enabling known items to be found

• It solves problems of inconsistency and variation of forms of names, titles, etc. found on physical manifestations of items

• But it also provides access to variant names through cross-references

• It establishes a uniform heading to group related items (collocation)

• It guarantees that entities, like authors, will have unique names so that the user can distinguish between those that share a common name


A Broader Definition

• In non-library settings, Cutter’s Objects can be seen to include many other means of access– May want to group items of a particular file type, in a

particular language, from a specific organization

• So, to generalize, any set of controlled values or rules governing the use of a metadata element could be considered authority control or an encoding scheme

• Thinking of it this way helps to provide the means to translate the principles into the metadata world, and links back to database modeling– One lack in many database systems is a set of clear rules for

determining values in fields– Ends up with the well-known dirty data problem, which eats

up lots of admin time in cleanup activities


Controlled vs. Uncontrolled Values

• Values for uncontrolled metadata elements are either copied from the information object directly or applied without rules– Examples are the title of a web page, or the number of pages

in a book• Values for controlled metadata elements are defined

by rules– We saw some examples of this last week in the Dublin Core

encoding schemes used for defining allowed values in some of the elements

• Control may be simple or complex– Rules defining a specific format (e.g., date) or a pre-defined

selection of values (e.g., language codes or format types) for a value can be applied easily

– More complex control may be needed where relationships between different values are important (forms of a person’s name, subject hierarchies, etc.)


Process of Name Authority Control

• Select a single and unique form of a name and enter (use that form as a value in) all records under that uniform name or heading

• Provide cross-references from the names not selected as preferred headings to the preferred name

• In library catalogs, authority control provided for names of persons, corporate bodies, etc., but not consistently for works.


Cross-References

• Equivalence relationships to control for variant names (see references)– Examples : Sears, M.E., search under Sears,

Minnie Earl.– United States Library of Congress search under

Library of Congress• Associative relationships for establishing relationships

among different entities (see also references)– Examples : Day Lewis, C. search also under

Nicholas Blake• Hierarchical relationships are also possible, but we

will focus more on these in the subject part of the course


Sample Authority Record

Sample simplified MARC authority record:

100 Rowley, Jennifer E. [authorized heading, or the heading used for access] 400 Rowley, Jennifer [name found on an item, used for cross reference

only] 400 Rowley, J.E. [name found on an item, used for cross reference

only]


See Reference Example

User Enters: Catalog to Authority Record Authority Rec. to Bibl. File

100 Rowley, Jennifer E. 10 items Rowley, Jennifer E. Rowley, J. E. 400 Rowley, J. E. 400 Rowley, J.

see reference field code in MARC

Authorized name field code in MARC


See Also Reference Example

SCREEN 1: You searched AUTHOR for: plaidy jean Titles Search Results 1 [3] Plaidy, Jean, 1906- Select this line item for an explanation of the above term. 2 [1] Plain, Belva. 3 [1] Plains Anthropological Society.

SCREEN 2, after user selects no. 1 from previous screen: ENTRY: Plaidy, Jean, 1906- NOTE: For works of this author entered under other names, search also under: Carr, Philippa, 1906- , Ford, Elbur, 1906- , Holt, Victoria, 1906- , Kellow, Kathleen, 1906- , Tate, Ellalice, 1906- … etc.


How Does it Work?

• To manage authority control, a storage mechanism must be created to hold the values and their associations (database, XML schema)– Usually in an authority control file– Holds the records for each authorized entry, its

associations and relationships, and change history

• At time of use, content items are associated with authority records through metadata– Result is a display that satisfies Cutter’s Objects by

bringing items with the same heading together and provide direct access to known items


How It Works

Vocabulary and Schema

Database

Site Server indexes

Search DLL

Modifiedstring

Searchresults

Input query

XML

XML


Problems with Authority Control

• Ayres’ article points out some issues with authority control– These are no different than common data

maintenance issues in any large system– The difficulty here is that they defeat the purpose

of the control in the first place– Again, points out the need to make sure you have

good processes and authority rules in place, and make the use of your control as easy as possible at the point of data entry

• You may decide that authority control is not appropriate if you can’t provide resources


Why Would You Do This?

• If you’re not in a library, is this kind of control worth your time, or possible?

• You’ll usually use legacy data for names– HR database is a primary source– Often have an LDAP server as well– Rarely is rigid authority control used in these

systems, and downstream users pay for it

• In intranet applications, integrating user identities can be a huge problem because authority control has not been used


Sweet Spots

• Corporate names– Essential in managing customer relationship data– Often can be purchased from outside vendors (Dow Jones,

Reuters) who maintain for their own purposes

• Organization names– Often one of the most important access points for users in an

intranet– Rarely have access outside your own group– Cross-company exposure can be very valuable

• People names– But make sure you work with HR and IT organizations to

build on their activity


Other Elements

• Any metadata element you’re using can benefit from authority control or an encoding scheme (in the broad sense we explored earlier in the class)– Even if you don’t need anything more than a rule,

make it explicit and if possible build it into your data entry system (e.g., date formats)

– If you have choices for term entry, define the values and restrict users to those alone (e.g., language codes, mime types, etc.)

– Where possible, use standards for your reference to avoid in-house maintenance


Alternatives to Authority Control

• Automatic indexing attempts to replicate many of the results of authority control– There are many methods for this, some very time

consuming, some processing intensive– Research applications are gradually being

incorporated into products• Decision on when to use remains the same

– What are your requirements for accuracy?– What are your business objectives?– What do your users need?

• Often a combination is the best solution– Use each where it makes the best business sense

Examples

• AGLS– http://www.naa.gov.au/records-management/create-capture-describ

e/describe/agls/agls-register-schemes-by-element.aspx

• Dublin Core– http://askdcmi.askvrd.org/default.aspx?cat=1732


http://www.naa.gov.au/records-management/create-capture-describe/describe/agls/agls-register-schemes-by-element.aspx

http://www.naa.gov.au/records-management/create-capture-describe/describe/agls/agls-register-schemes-by-element.aspx

http://askdcmi.askvrd.org/default.aspx?cat=1732




Assignment Part 2: Authority Control for Your Metadata Elements

• Due at beginning of class Week 6• 20% of final grade• Spend some time examining the resources

you draw your elements from so that you can provide control

• Think about the people actually describing the content, and how they will know how to populate your elements with consistent values

• Don’t work on subject elements, those are for your final assignment


Questions?

• If not, take a break!!!

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