Freebase Schema

Freebase Schema
Jamie Taylor

Wednesday, December 8, 2010

Goals

• Schema: The Freebase Data Model
• Schema as API
• Schema patterns


Freebase is a collection of facts
Soﬁa Coppola directed Marie Antoinette

{
{
{

Freebase only contains
nodes and Links

Freebase is a Graph


Freebase is a labeled Graph
child wrote

directed
parent sibling

directed

starred_in directed

starred_in


Schema

"All the things you can say
about something in Freebase"

Schema is the data model for Freebase


All nodes are “/type/object”
/m/02vyw /people/person
id type
type /ﬁlm/director

[{
/type/object/name
  "id":"/m/02vyw", name
  "name":null,
  "type":[{}]
“Francis Coppola”
}]


Types suggest properties to use
/m/02vyw
id
lm
/ﬁ
or
ct
ire
/d
lm
/ﬁ

/type/object/id /en/bram_stokers_dracula

Queries follow schema

[{
   "id": "/en/francis_ford_coppola",
   "/ﬁlm/director/ﬁlm": [{
   "id":null,
"name":null
   }]
}]


Properties link the graph together
/m/02vyw
id
lm
/ﬁ
or
ct
ire

ten _by
/d

wri t
lm
/ﬁ

/type/object/id /en/bram_stokers_dracula

Queries follow schema

[{
   "id": "/en/francis_ford_coppola", Name is returned
(how to get ID?)
   "/ﬁlm/director/ﬁlm": [{ How to get all the
   "id": "/en/bram_stokers_dracula", writters for all of
Coppola’s movies?
"written_by":null
   }]
}]


Core Concepts


Core Concepts

Instance:
• Topic: "a thing in the world"
• Blade Runner, Ridley Scott, NBC, Last Proof

Schema:
• Types - Categorical collections of instances
• Properties - Relationships between instances


Core Concepts

An instance may have multiple Types
• "Co-Types" (Types are mix-ins)
• Arnold Schwartzeneger
• Person, Actor, Politician, Sports Figure


Lessons from everyday vocabulary

Wikipedia Word Frequency

20000000

18000000

16000000

14000000

12000000
Frequency

10000000

8000000

6000000

4000000

2000000

0
0 20 40 60 80 100 120
Rank
Data from Victor S. Grishchenko


Schema Principle #1
Event Example:
-Film Festival
-Battle of Waterloo

Use Co-Types Liberally:
Use a few large, encompassing Types to
provide general information

Use several smaller, ﬁne grained Types to
provide detailed information


Core Concepts Relational DB
vs
RDF

Properties are deﬁned on Types
• Properties are the vocabulary for a speciﬁc Type
• An instance must be “an instance of a type”
before it can use the Type’s properties to describe
itself


Core Concepts Expected Type ~ RDFS Range

• A Property Value has a speciﬁc Type
• "Expected Type"

• A Property has exactly one Expected Type

Manufactures


Core Concepts

Expected Types (Property Values):
• Value Types (literals)
• String (two ﬂavors), Integer, Float, DateTime, boolean

• Object Types
• Everything Else


/type/object contrast to common
topic

Everything in Freebase has this Type
Provides basic properties
• Type

• Name

• .......

All other Properties come from some other Type!


/common/topic
"Topics"
• Things we have discourse about
• Provides properties:
• Alias

• Article

• Image

• Weblinks

• Assumed to be an "Included Type" for any
"standard" type

Schema Patterns

Compound Value
Mediator
Phylogeny
Enumeration


Compound Value complex literal

Two or more properties which can only be
interpreted with regard to one another
Population
• Dated Integer ("when did this location have that many people")

Movie Budget
• Dated money value

• Date, Currency, Amount

Ticker Symbol
• Exchange, Symbol


Compound Value
currency
estimated_budget amount 31MM

{
  "id": "/en/apocalypse_now",
valid_date 1979
  "type": "/film/film",
  "estimated_budget": [{
  "currency": null,
  "amount": null,
  "valid_date": null
  }]
}

Mediator combine date annotation and
character = tv character

An annotation on the link between two Topics
• Requires an object between the two Topics
• The Topics become separated by two properties

actor performance ﬁlm

character

• Also useful for indicating the dates when a
relationship existed (e.g., education, employment, etc.)

Mediator

{
  "id": "/en/marie_antoinette_2006",
  "type": "/film/film",
  "starring": [{
   "actor":null,
   "character":null
  }]
}

Phylogeny
Used when instances form a hierarchy
Phylogeny properties have an expected
Type which is the same as the Type on
which the property is deﬁned.

Examples:
• /location/location/containedby

• /computer/computer/parent_model

• /tv/tv_program/spin_offs


Phylogeny

{
  "id": "/en/fairfax_california",
  "/location/location/containedby": [{
  "id": null,
  "containedby": [{
  "id": null Why can I use the
short name??
  }]
  }]
}

Enumerated Value
Closed collection of “values” for a property
Constrains relations to ﬁxed set of objects

• /people/person/gender
{ female, male, other }

• /visual_art/visual_artist/art_forms
{ drawing, painting, print making, photography.... }


Explore the Freebase Graph
child wrote

directed
parent sibling

directed

starred_in directed

starred_in



[{
"id": null,
"type": "/ﬁlm/director"
}]



[{
  "id": null,
  "type": "/ﬁlm/director",
  "/people/person/children": [{
   "id": null,
  }]
}]



[{
  "id": null,
  "ﬁlm":[ ],
   "id": null,
   "ﬁlm":[ ]
  }]
}]


[{
  "id": null,
  "ﬁlm": [ ],
   "id": null,
   "ﬁlm": [{
   "name":null,
   "starring": [{
   "actor": null
   }]
   }]
  }]
}]


namespace

It’s all nodes
/
pe
ople
( key
y) )
(ke
film

domain

type
domain /people

and links!
type
/film

e
insta anc
nce type inst

nam
e

y)
(ke
e
typ
"domain"

son
type

film

per
(key
name "property"

ins
ce type

)

tan
propert
tan ies
ins

ce
ins
tan
"type" ce

instance
type
nam
e type instance typ
e
property
instance
expected_type
ce
tan
ins

na
ins

m
nce

e
tan
insta

ce
"expected type"

type
property

type type type
typ
type type
e
type properties na
expected
_type date_time
me
na
na me
me na
m
e
"person" "date of birth"

nce
"film"

instance
instance

insta
"actor"

e LEGEND
film typ

name
"Blade Runner" /type/object
starring

/type/object + /common/topic
film

obj type
film
character performance

/namespace
e
nam
"Rick Deckard"
outgoing incoming
actor

keyvalue (key)
film

actor out
goin
gp
rop
person e e rty
typ
type literal value
nam
th e
_o f_bir
date
"Harrison Ford"
1942-07-13


Domains, Bases and Commons

"commons" individual's "bases"
promo
te

Blade
Runner

"domains"


Questions?!

Docs: www.freebase.com/docs
Wiki: wiki.freebase.com
Mailing List: lists.freebase.com


Freebase Schema

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