Moving toward formalisation COMP60421 Sean Bechhofer - PowerPoint PPT Presentation

Moving toward formalisation COMP60421 Sean Bechhofer sean.bechhofer@manchester.ac.uk � (thanks to Bijan Parsia for slides)

Previously... • We started the acquisition process... – We elicited tacit knowledge – In a variety of ways – about a set of terms (or concepts) • But even there we could get more explicit – Normalising terms (e.g., “symmetry or symmetric”?) – Hierarchy (and other direct relations between terms) – Categorizing terms (e.g., as modifiers or self-standing) – 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 • Let’s consider a simple text passage: – There are several sorts of domesticated animals, though by far the most are mammals (like us!). For example, our faithful pets, cats and dogs, are clearly domesticated (or we would not keep such dangerous carnivores in our homes), as is the delicious cow which is farmed in ever increasing numbers.

Term extraction • Highlighting! – There are several sorts of domesticated animals, though by far the most are mammals (like us!). For example, our faithful pets, cats and dogs, are clearly domesticated (or we would not keep such dangerous carnivores in our homes), as is the delicious* 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 • We pull these out – domesticated – animals – mammals – us – pets – cats – dogs – dangerous – carnivores – homes – delicious – cow – farmed – increasing – numbers

Term extraction • We pull these out – domesticated – animals – mammals – us – pets – cats These are quite odd – dogs but in different ways – dangerous – carnivores – homes – delicious – cow – farmed – increasing – numbers

Term extraction • We pull these out – domesticated – animals – mammals – us – pets – cats These are similar – dogs but have different levels – dangerous – carnivores of generality, and non- – homes standard spelling – delicious – cow – farmed – increasing – numbers

Grouping • Base animal categories (nouny terms) – animals – cats – dogs – mammals – cow – us • Ways an animal can be (adjectivally terms) – domesticated – pets – dangerous – carnivores – delicious – farmed • Stuff – homes – increasing – numbers

Grouping • Base animal categories (nouny terms) – animals – cats – dogs – mammals – cow – us • Ways an animal can be (adjectivally terms) – domesticated – pets – dangerous – carnivores – delicious Should we care about – farmed these? • Stuff – homes – increasing – numbers

A key slogan • Representations are – context sensitive, and – interest relative • Context sensitive? – Application or kind of application • Interests? – Application needs • Teaching, categorising, data acquisition – Audience • Children, lay people, different disciplines, clinicians vs. researchers • Establish context and relevant interests – In this case the context is this class and my interests are working up a reasonable example

Grouping • Base animal categories (nouny terms) – animals – cats – dogs – mammals – cow – us • Ways an animal can be (adjectivally terms) – domesticated – pets – dangerous – carnivores – delicious Should we care about – farmed these? • Stuff – homes No! (Why?) – increasing – numbers

Normalise Terms! • Base animal categories (nouny terms) – animals – cats Standardise number – dogs – mammals – cow – us • Ways an animal can be (adjectivally terms) – domesticated – pets – dangerous – carnivores – delicious – farmed

Normalise Terms! • Base animal categories (nouny terms) – Animal – Cat – Dog – Mammal – Cow Make explicit – us • Ways an animal can be (adjectivally terms) – domesticated – pets – dangerous – carnivores – delicious – farmed

Normalise Terms! • Base animal categories (nouny terms) – Animal – Cat – Dog – Mammal – Cow – Human • Ways an animal can be (adjectivally terms) – domesticated – pets – dangerous These seem extra – carnivores (not of interest), and we can – delicious adjectivize the rest – farmed

Normalise Terms! • Base animal categories (nouny terms) – Animal – Cat – Dog – Mammal – Cow – Human • Ways an animal can be (adjectivally terms) – Domesticated – Pet – Carnivorous We have some background – Farmed knowledge we can use to “round out” these terms

Normalise Terms! • Base animal categories (nouny terms) – Animal – Cat – Dog – Mammal – Cow – Human • Ways an animal can be (adjectivally terms) – Domesticated – Pet – Farmed We have some background – Wild knowledge we can use to – Carnivorous “round out” these terms – Herbivorous (using elicitation techniques) – Omnivorous

Organise terms • Base animal categories (nouny terms) – General • Animal Both General and Specific • Mammal – Specific • Cat • Dog • Cow • Human • Ways an animal can be (adjectivally terms) – General • Domesticated Contraries! • Wild • Carnivorous • Herbivorous • Omnivorous – Specific Contraries? • Pet • Farmed

Organise terms • Self-Standing (nouny terms) – General • Animal • Mammal – Specific • Cat • Dog • Cow • Human • Modifiers (adjectivally terms) – General What terms are definable? • Domesticated • Wild • Carnivorous • Herbivorous • Omnivorous – Specific • Pet • Farmed

Organise terms • Self-Standing (nouny terms) – General • Animal • 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

Capturing in an actionable form • We can capture what we’ve done – in a structured way – and get some benefits!

Iterative process • Building the representation is informative – Definitions elicit new terms – Interests and Context tell us when a fixed point is reached • Fatigue! Fatigue works... • Until now, entirely human process – Having the structured form helps a little • Easier search/browsing – But no “content” feedback – For this, we need to understand • what we want to represent • what we can represent!

So far... • We are well into KA – Term extraction – Initial regimentation • Normalisation • Hierarchical organisation • Categorisation – Started additional capture • Adding definitions • Ready to consider the next step – Proto-Formalisation! • Remember: – Interest sensitive and context relative – We’re looking for benefits (to way against costs) • But first... 22

Remember our passage • With highlighting! – There are several sorts of domesticated animals, though by far the most are mammals (like us!). For example, our faithful pets, cats and dogs, are clearly domesticated (or we would not keep such dangerous carnivores in our homes), as is the delicious yet docile cow which is farmed in ever increasing numbers. • Why not: – There are several sorts of domesticated animals, though by far the most are mammals (like us!). For example, our faithful pets, cats and dogs, are clearly domesticated (or we would not keep such dangerous carnivores in our homes), as is the delicious yet docile cow which is farmed in ever increasing numbers. 23

What terms should go in? • It depends! – Interests and context – Resources, including • Time • Energy • Representational capabilities • Skill, etc. • Fewer than all – A generally good rule of thumb • Other than what’s there – Another good rule of thumb! – “Fleshing out” • Organisational needs (e.g., “LivingThing”) • Representational needs (e.g., “eats”) • Coverage, “completeness” (e.g., “omnivore”) 24

What matters? How do we tell? Symmetry in biology is the balanced distribution of duplicate body parts or shapes. The body plans of most multicellular organisms exhibit some form of symmetry, either radial symmetry orbilateral symmetry or "spherical symmetry". A small minority exhibit no symmetry (are asymmetric). � � In nature and biology, symmetry is approximate. For example, plant leaves, while considered symmetric, will rarely match up exactly when folded in half. � 25

What terms are definable? • Self-Standing (nouny terms) • New Terms – General • Animal • Mammal – Specific • Cat • Dog • Cow • Human • Modifiers (adjectivally terms) – General • Domesticated • Wild • Carnivorous • Herbivorous • Omnivorous – Specific • Pet • Farmed 26