1. Concept Description Vectors and the 20 Questions Game
Włodzisław Duch
Tomasz Sarnatowicz
Julian Szymański

2. Permanent container for general knowledge
Semantic Memory
Permanent container for general knowledge

3. Hierarchical Model Collins & Quillian, 1969

4. Semantic network Collins & Loftus, 1975

5. Semantic Memory

6. All the concepts and keywords create a
Semantic Space
All the concepts and keywords create a
semantic matrix

7. Concept Description Vectors
CDV – a vector of properties describing a single concept
Most of elements are 0’s – sparse vector

8. Data Sources I Machine readable dictionaries and ontologies: Wordnet
ConceptNet
Sumo/Milo ontology

9. Data Sources II Dictionaries data retrieval On-line sources Approach
Merriam Webster
Wordnet (gloss)
MSN Encarta
Approach
Word morphing
Phrases extraction (with POS tagger)
Statistical analysis

10. Data access Binary dictionary search
220 =
Binary search – not acceptable in complex semantical applications
Narrowing concept space by subsequent queries

11. 20 Questions Game
Algorithm
p(keyword=vi) is fraction of concepts for which the keyword has value vi
Candidate concepts O(A) are selected according to:
O(A) = {i; |CDVi-A| is minimal}
where
CDVi is a vector for concept i and A is a partial vector of retrieved answers

12. Word puzzles 20Q game reversed Concept – known
Keywords – the ones that would lead to the concept