SimilarityBased Object Metadata Browser

1
Similarity-Based Object Metadata Browser

• Progress Report
• Rod McFarland
• CPSC 533C

2
Outline

• Background
• Problem
• Concept
• Concept Development
• Implementation
• Demonstration
• Future Enhancements

3
Background

• UBC Learning Object Metadata Repository
• What is a Learning Object?
• Not what we usually consider objects to be
• Metadata Specifications IMS, CanCore
• XML schema for describing objects
• Web-based client interface (JSP/XML/MySQL)
• http//flora.cs.ubc.ca8080/learningobject

4
Problem

• Metadata provides flexible and comprehensive
  descriptions of general objects
• Traditional search interfaces tend to offer
  searching on only a few descriptive dimensions
• CanCore metadata specification has 41
  non-placeholder elements any of these could
  potentially be searchable

5
Concept

• Use a browsing strategy based on similarity to
  a known object
• Define similarity
• Depends on the data type (Language strings,
  dates, pure number, standard vocabularies)
• How to handle varying multiplicity among metadata
  records
• Selection of known object
• Via conventional text-based search
• Via specification of ideal object

6
Concept

• Originally envisioned a network view with pairs
  of objects of nonzero similarity linked by lines
  of length inversely proportional to the
  similarity.
• A bit of thought shows that this wont work
  without a lot of work, similarity is not a
  metric
• New idea similar objects radially arranged
  around known object, with distance inversely
  proportional to similarity

7
Concept Development

• Similarity can be adjusted. As an aggregate
  measure, the component similarities can be given
  different weights
• Selecting objects in the cloud will change the
  focus object and cause a new display to be
  generated
• A path through the object space can indicate
  what objects have been visited

8
Implementation

• Intended to be embedded in a Web page, so
  development will be in Java/Swing
• Few available LO records, so modifying project to
  use a different source of objects (sentences in a
  text file)
• Since this was not intended to be a text browser,
  not offering a full-text view
• demo

9
Future Enhancements (soliciting opinions and
suggestions)

• Prototype object to specify initial search focus
• Color coding of dots to indicate most related
  dimension
• Animated transition on focus object change
• Make the visited path feature more useful
  how?
• Single-click or hover over object to see metadata
  detail
• Change scale of display (by dragging mouse away
  from centre)
• How to handle ghost objects
• Negative weighting
• Multiple options for computing similarity for a
  data type