Previously... We started the acquisition process... We elicited - PowerPoint PPT Presentation

Previously... • We started the acquisition process... – We elicited tacit knowledge Moving toward formalisation – In a variety of ways – about a set of terms (or concepts) COMP60421 • But even there we could get more explicit – Normalising terms (e.g., “symmetry or symmetric”?) – Hierarchy (and other direct relations between terms) (Slides by) Bijan Parsia – Categorizing terms (e.g., as modifiers or self-standing) bparsia@cs.man.ac.uk – Constraining and defining terms • 2 important next steps – Getting even more explicit and precise • Refining our proto-represntation – Getting actionable • Building a representation Term extraction Term extraction • Let’s consider a simple text passage: • Highlighting! – There are several sorts of domesticated animals, though by far – There are several sorts of domesticated animals, though by far the most are mammals (like us!). For example, our faithful pets, the most are mammals (like us!). For example, our faithful pets, cats and dogs, are clearly domesticated (or we would not keep cats and dogs, are clearly domesticated (or we would not keep such dangerous carnivores in our homes), as is the delicious such dangerous carnivores in our homes), as is the delicious* cow which is farmed in ever increasing numbers. yet docile cow which is farmed in ever increasing numbers. *Note that Bijan is a vegetarian! But he does remember some exceeding delicious cows.

Term extraction Term extraction • We pull these out • We pull these out – domesticated – domesticated – animals – animals – mammals – mammals – us – us – pets – pets – cats – cats These are quite odd – dogs – dogs – dangerous but in different ways – dangerous – carnivores – carnivores – homes – homes – delicious – delicious – cow – cow – farmed – farmed – increasing – increasing – numbers – numbers Term extraction Grouping • Base animal categories (nouny terms) • We pull these out – animals – cats – domesticated – dogs – animals – mammals – mammals – cow – us – us – pets • Ways an animal can be (adjectivally terms) – cats These are similar – dogs – domesticated – dangerous but have different levels – pets – carnivores of generality, and non- – dangerous – homes – carnivores standard spelling – delicious – delicious – cow – farmed – farmed • Stuff – increasing – homes – numbers – increasing – numbers

Grouping A key slogan • Base animal categories (nouny terms) • Representations are – animals – cats – context sensitive, and – dogs – interest relative – mammals • Context sensitive? – cow – us – Application or kind of application • Ways an animal can be (adjectivally terms) • Interests? – domesticated – Application needs – pets • Teaching, categorising, data acquisition – dangerous – Audience – carnivores • Children, lay people, different disciplines, clinicians vs. researchers – delicious Should we care about • Establish context and relevant interests – farmed these? • Stuff – In this case the context is this class and my interests are – homes working up a reasonable example – increasing – numbers Grouping Normalise Terms! • Base animal categories (nouny terms) • Base animal categories (nouny terms) – animals – animals – cats – cats Standardise number – dogs – dogs – mammals – mammals – cow – cow – us – us • Ways an animal can be (adjectivally terms) • Ways an animal can be (adjectivally terms) – domesticated – domesticated – pets – pets – dangerous – dangerous – carnivores – carnivores – delicious – delicious Should we care about – farmed – farmed these? • Stuff – homes No! (Why?) – increasing – numbers

Normalise Terms! Normalise Terms! • Base animal categories (nouny terms) • Base animal categories (nouny terms) – Animal – Animal – Cat – Cat – Dog – Dog – Mammal – Mammal – Cow – Cow – us Make explicit – Human • Ways an animal can be (adjectivally terms) • Ways an animal can be (adjectivally terms) – domesticated – domesticated – pets – pets – dangerous – dangerous These seem extra – carnivores – carnivores (not of interest), and we can – delicious – delicious adjectivize the rest – farmed – farmed Normalise Terms! Normalise Terms! • Base animal categories (nouny terms) • Base animal categories (nouny terms) – Animal – Animal – Cat – Cat – Dog – Dog – Mammal – Mammal – Cow – Cow – Human – Human • Ways an animal can be (adjectivally terms) • Ways an animal can be (adjectivally terms) – Domesticated – Domesticated – Pet – Pet – Carnivorous – Farmed We have some background We have some background – Farmed – Wild knowledge we can use to knowledge we can use to – Carnivorous “round out” these terms “round out” these terms – Herbivorous (using elicitation techniques) – Omnivorous

Organise terms Organise terms • Base animal categories (nouny terms) • Self-Standing (nouny terms) – General – General • Animal • Animal • Mammal Both General and Specific • Mammal – Specific – Specific • Cat • Cat • Dog • Dog • Cow • Cow • Human • Human • Ways an animal can be (adjectivally terms) • Modifiers (adjectivally terms) – General – General What terms are definable? • Domesticated • Domesticated Contraries! • Wild • Wild • Carnivorous • Carnivorous • Herbivorous • Herbivorous • Omnivorous • Omnivorous – Specific – Specific Contraries? • Pet • Pet • Farmed • Farmed Organise terms Capturing in an actionable form • Self-Standing (nouny terms) • We can capture what we’ve done – General – in a structured way • Animal – and get some benefits! • Mammal – Specific • Cat • Dog • Cow • Human • Modifiers (adjectivally terms) – General What terms are definable? • Domesticated • Wild • Carnivorous “An animal which eats only meat” • Herbivorous • Omnivorous – Specific Existing term New terms • Pet • Farmed

Iterative process • Building the representation is informative – Definitions elicit new terms – Interests and Context tell us when a fixed point is reached Toward Definitions • Fatigue! Fatigue works... COMP60421 • Until now, entirely human process – Having the structured form helps a little • Easier search/browsing (Slides by) Bijan Parsia – But no “content” feedback bparsia@cs.man.ac.uk – For this, we need to understand • what we want to represent • what we can represent! Recap... Remember our passage • We are well into KA • With highlighting! – Term extraction – There are several sorts of domesticated animals, though by – Initial regimentation far the most are mammals (like us!). For example, our • Normalisation faithful pets, cats and dogs, are clearly domesticated (or we • Hierarchical organisation would not keep such dangerous carnivores in our homes), • Categorisation as is the delicious* yet docile** cow which is farmed in ever – Started additional capture increasing numbers. • Why not: • Adding definitions • Ready to consider the next step – There are several sorts of domesticated animals, though by far the most are mammals (like us!). For example, our – Proto-Formalisation! faithful pets, cats and dogs, are clearly domesticated (or we • Remember: would not keep such dangerous carnivores in our homes), – Interest sensitive and context relative as is the delicious* yet docile** cow which is farmed in ever – We’re looking for benefits (to way against costs) increasing numbers. • But first... *Keep Bijan’s vegetarianism firmly in mind! **”Docile” never makes it in. 23 24