Advance Information Retrieval Topics

1
Advance Information Retrieval Topics

• Hassan Bashiri

2
Information Filtering
3
Agenda

• Information filtering
• Automatic profile learning
• Social filtering
• Training Strategies

4
Information Access Problems
Different Each Time
Retrieval
Information Need
Data Mining
Stable
Filtering
Stable
Different Each Time
Collection
5
Indexing and Complexity
6
Agenda

• Inverted indexes
• Computational complexity

7
An Example
Postings
Term
Doc 1
Doc 2
Doc 3
Doc 4
Doc 5
Doc 6
Doc 7
Doc 8
Inverted File
aid
0
0
0
1
0
0
0
1
AI
4, 8
A
all
0
1
0
1
0
1
0
0
AL
2, 4, 6
back
1
0
1
0
0
0
1
0
BA
1, 3, 7
B
brown
1
0
1
0
1
0
1
0
BR
1, 3, 5, 7
come
0
1
0
1
0
1
0
1
C
2, 4, 6, 8
dog
0
0
1
0
1
0
0
0
D
3, 5
fox
0
0
1
0
1
0
1
0
F
3, 5, 7
good
0
1
0
1
0
1
0
1
G
2, 4, 6, 8
jump
0
0
1
0
0
0
0
0
J
3
lazy
1
0
1
0
1
0
1
0
L
1, 3, 5, 7
men
0
1
0
1
0
0
0
1
M
2, 4, 8
now
0
1
0
0
0
1
0
1
N
2, 6, 8
over
1
0
1
0
1
0
1
1
O
1, 3, 5, 7, 8
party
0
0
0
0
0
1
0
1
P
6, 8
quick
1
0
1
0
0
0
0
0
Q
1, 3
their
1
0
0
0
1
0
1
0
TH
1, 5, 7
T
time
0
1
0
1
0
1
0
0
TI
2, 4, 6
8
The Finished Product
Term
Postings
Inverted File
aid
AI
4, 8
A
all
AL
2, 4, 6
back
BA
1, 3, 7
B
brown
BR
1, 3, 5, 7
come
C
2, 4, 6, 8
dog
D
3, 5
fox
F
3, 5, 7
good
G
2, 4, 6, 8
jump
J
3
lazy
L
1, 3, 5, 7
men
M
2, 4, 8
now
N
2, 6, 8
over
O
1, 3, 5, 7, 8
party
P
6, 8
quick
Q
1, 3
their
TH
1, 5, 7
T
time
TI
2, 4, 6
9
Cross-Language Information Retrieval
10
Agenda

• Cross-language IR
• Controlled vocabulary
• Automatic indexing
• Free text
• Evaluation
• User interface design

11
What is CLIR?
Users enter their query in one language and the
search engine retrieves relevant documents in
other languages.
English Query
French Documents
Retrieval System
12
Cross-Language Text Retrieval
Query Translation
Document Translation
Text Translation Vector Translation
Controlled Vocabulary Free Text
Knowledge-based
Corpus-based
Ontology-based Dictionary-based
Term-aligned Sentence-aligned
Document-aligned Unaligned
Thesaurus-based
Parallel Comparable
11
13
Agenda

• Retrieval of still images
• Audio indexing

14
Retrieval System Interfaces
15
Agenda

• Query interface
• Selection interface
• Examination interface
• Document delivery

16
Retrieval System Model
User
Query Formulation
Detection
Selection
Index
Examination
Docs
Indexing
Delivery
17
Query Formulation
User
Query Formulation
Detection
Index
18
Starfield
19
Search Engine Organization
20
NLP in IR
21
The Different Levels of Language Analysis
1-Phonetic or Phonological Level 2-Morphological
Level 3-Syntactic Level 4-Semantic
Level 5-Discourse Level
22
How Information Retrieval Works
Step 1 Document Processing Step 2 Query
Processing Step 3 Query Matching Step 4 Ranking
Sorting
23
Intelligent Information RetrievalorKnowledge
Based IR
24
What Is Different From IR?

• IR is more concerned with words and concepts.
• IIR or KBIR is more concerned about relations.
• Most of IR models assume term independence.
• IIR or KBIR acknowledges existence of
  relationships.
• IR more suitable for large scale and general
  retrieval
• IIR or KBIR more suitable for domain specific
  tasks.

25
Knowledge Based IR
26
IIR-KBIR

• Expectation or Interaction With User
• Objects
• KB
• Relation Between the objects
• Reasoning
• Learning
• Relation Extraction

27
Experiments in Farsi Retrieval
28
Retrieval Models Investigated

• Fuzzy Logic
• MMM, Paice
• Vector Space
• Probabilistic, BM25
• N-Grams
• Combinational