Task-Based Support
in Search Engines
Darío Garigliotti

University of Stavanger, Norway
Outline
• Motivation

• Type-Aware Entity Retrieval

• Target Entity Type Identification

• Entity-Oriented Search Intents

• Task-Based Query Suggestions

• Task Recommendations

• Conclusions and Future Directions
2
Motivation
Motivation
• Today's web search experience aims to understand
the user query
4
Motivation
• Today's web search experience aims to understand
the user query
5
Motivation
• Today's web search experience aims to understand
the user query
6
Motivation
• Today's web search experience aims to understand
the user query

• A way to organize information is via structured
knowledge centered around entities

• Large knowledge repositories and knowledge bases
have become available
7
Motivation
8
Motivation
9
Motivation
10
Motivation
11
• Underlying search goal is often a complex and
knowledge-intensive task
Motivation
12
Motivation
13
Motivation
14
• Underlying search goal is often a complex and
knowledge-intensive task

• For example, to plan a travel

- How to get there?

- Where to stay?

- What to do?

• Task completion would provide support for the
user when accomplishing complex search
tasks
Motivation
15
Roadmap
Type-Aware
Entity
Retrieval
Task-Based
Search
Entity-Oriented
Search
Intents
16
Type-Aware
Entity Retrieval
An example
• Searching for wedding cakes
cake shops
Konditoriet i
Sandnes
Olja's Kake
Boutique
Baker
Corner Lura
18
An example
• Searching for wedding cakes
wedding cake shops
Stavanger
Conditori
Olja's Kake
Boutique
Gjestalveien
Conditori
19
• Entity retrieval is the task of obtaining a
ranked list of entities relevant to a search
query

• We investigate the utilization of entity type
information for entity retrieval
Entity Retrieval
20
…
Shop
… ……
Company
Organization …
Stavanger
Conditori
Bank
Law Firm …
Entity types
• A characteristic property of entities is that they
are typed

• Types are organized in hierarchies

(or taxonomies)
21
…
Shop
… ……
Company
Organization …
cake shopscake shops
Bank
Law Firm …
• Target types: types of entities

sought by the query
Target entity types
22
Type-aware Entity Retrieval
• Type information is known to improve entity
retrieval 

• Yet it is a multifaceted problem
query entity
wedding cake shops
target types
Stavanger Conditori
term-based
similarity
type-based
similarity
… …
entity types
23
How can entity type information

be utilized in ad-hoc entity retrieval?
24
• We assume oracle-given type information

Type-aware Entity Retrieval
…
Shop
… ……
Company
Organization …
cake shopscake shops
Bank
Law Firm …
25
• We assume oracle-given type information

• We identify dimensions in utilizing entity
type information

- Type taxonomy

- Type representation

- Retrieval model
Type-aware Entity Retrieval
26
• Which type taxonomy to use?

- DBpedia Ontology (7 levels, 600 types)

- Freebase Types (2 levels, 2K types)

- Wikipedia Categories (34 levels, 600K types)

- YAGO Taxonomy (19 levels, 500K types)

• These vary a lot in terms of hierarchical
structure and in how entity-type assignments
are recorded
Type-aware Entity Retrieval
27
• How to represent the hierarchical information?

Type-aware Entity Retrieval
28
• How to use type information into entity
retrieval?

• Retrieval task is defined in a generative
probabilistic framework P(q | e)

• Both query and entity are considered
in the term space as well as in the type
space

Type-aware Entity Retrieval
29
• (Strict) Filtering model

Type-aware Entity Retrieval
30
• (Soft) Filtering model

Type-aware Entity Retrieval
31
• Interpolation model

Type-aware Entity Retrieval
32
• We assume oracle-given type information

• We conduct an evaluation of dimensions in
utilizing entity type information

- Type taxonomy

- Type representation

- Retrieval model

• We use a strong text-based baseline

• We test with the DBpedia Entity collection v2
Type-aware Entity Retrieval
33
• Wikipedia, in combination with the most
specific type representation, performs best

• Hierarchical relationships from ancestor
types improve retrieval effectiveness, but
most specific types provide the best
performance

• Results regarding most effective type-aware
retrieval model vary across configurations
Type-aware Entity Retrieval
34
Roadmap
Type-Aware
Entity
Retrieval
Utilizing Entity Type
Information
35
Target Entity Type
Identification
Target Type Identification
• "We assume oracle-given type information"

37
Target Type Identification
• "We assume oracle-given type information"

38
Target Type Identification
• "We assume oracle-given type information"

- How to identify target entity types?

- How do these target types automatically
identified perform for type-aware entity
retrieval?
39
How can we automatically

identify target entity types?
40
Target Type Identification
• We revisit the task of hierarchical target
type identification

• Task: to find the main target types of a
query, from a type taxonomy, such that
these are the most specific category of
entities that are relevant to the query.

If no matching type can be found in the
taxonomy then the query is assigned a
special NIL-type
41
Target Type Identification
• We develop a Learning-to-Rank approach

• We evaluate it using a purpose-built test
collection
42
Target Type Identification
43
• Our method combines baseline,
knowledge base, and type label features
• We also conduct an evaluation utilizing,
rather than a target types oracle, target
entity types automatically identified
44
Automatic types for Entity
Retrieval
Automatic types for Entity
Retrieval
45
We identify and evaluate dimensions in utilizing
target entity type information for ad-hoc entity
retrieval.
We build a test collection for target entity type
identification, and develop and evaluate a
Learning-to-Rank approach for this problem.
SUMMARY
46
Roadmap
Type-Aware
Entity
Retrieval
Utilizing Entity Type
Information
Identifying Target
Entity Type Information
47
Entity-Oriented
Search Intents
Entity-Oriented Search
Intents
• Intent: the underlying user need in a entity-
oriented search query

- For example, the intent of booking a hotel room
• Refiner: a way to express an intent in an
entity-oriented query

- For example, for booking a hotel room:
"booking", "book", "reservation", "rooms"
49
• Searching about a fashion designer
An example
50
vivienne westwood age
An example
51
vivienne westwood age
An example
78 years
April 8, 1941
52
vivienne westwood age
An example
78 years
April 8, 1941
53
An example
54
vivienne westwood instagram
An example
55
vivienne westwood instagram
An example
instagram.com/viviennewestwood/
56
vivienne westwood instagram
An example
instagram.com/viviennewestwood/
57
An example
58
vivienne westwood customer care
An example
59
vivienne westwood customer care
An example
60
What do entity-oriented queries ask for,

and how can they be fulfilled?
61
<fashion designer> instagram
Understanding entity-
oriented search intents
• We obtain a collection of type-level query patterns
stella mccartney instagram
vivienne westwood instagram
62
Understanding entity-
oriented search intents
• We obtain a collection of type-level query patterns

• Pick a Freebase type if it covers 100+ prominent entities

• Get query suggestions for top 1000- entities per type

• For each query, replace entity by type

• Aggregate all frequencies for each (type, refiner) pair

• Filter out all type-level refiners with frequency of 4-

• Select 50 representative types by stratified sampling

63
Understanding entity-
oriented search intents
• We define a scheme of intent categories

64
Understanding entity-
oriented search intents
• We define a scheme of intent categories

Website
65
Understanding entity-
oriented search intents
• We define a scheme of intent categories

PropertyWebsite
66
Understanding entity-
oriented search intents
• We define a scheme of intent categories

PropertyWebsite
Service 67
Understanding entity-
oriented search intents
• We define a scheme of intent categories

PropertyWebsite
Service Other68
Understanding entity-
oriented search intents
• We define a scheme of intent categories

- Website, Property, Service, Other
=> Website
=> Property
=> Service
vivienne westwood age
vivienne westwood instagram
vivienne westwood customer care
69
Understanding entity-
oriented search intents
• We annotate 2.3K+ unique type-level refiners
with intent category via crowdsourcing

• We observe the proportions of refiners in each
category
Property: 28.6%
Service: 54.06%
Website: 5.34%
Other: 12.08%
70
Understanding entity-
oriented search intents
71
organization
business operation
chemical compound
film
location
event
food
hotel
disease
restaurant
travel destination
0
50
100
150
200
250
university
house
person
newspaper
airport
basketball player
album
professional sports team
game
artwork
0
50
100
150
200
railway
human language
tv station
political party
amusement park
exhibition venue
chef
programming language
academic institution
netflix genre
0
20
40
60
80
100
120
war
currency
blogger
hobby
football match
sports championship
star
muscle
olympic sport
company
0
10
20
30
40
50
WroSicaO cycOone
kingdoP
PedicaO sSeciaOWy
coPic book SubOisher
oiO fieOd
Wower
beer counWry region
eOecWion
asWeroid
beOief
0
10
20
30
40
50
3roSerWy
WebsiWe
Service
2Wher
We propose a scheme of entity-oriented search
intent categories.
We annotate a collection of query refiners using
the scheme, and observe that there is a large
proportion of service-oriented intents.
SUMMARY
72
Roadmap
Type-Aware
Entity
Retrieval
Entity-Oriented
Search
Intents
Utilizing Entity Type
Information
Identifying Target
Entity Type Information
Understanding Entity-
Oriented Search Intents
73
How can we build a knowledge base

of entity-oriented search intents?
74
1. Intents searched for a type of entities

paris map, sydney map => [city] map
2. Categories assigned to refiners

vivienne westwood instagram => Website
vivienne westwood age => Property
vivienne westwood customer care => Service
3. Multiple refiners expressing an intent

"booking", "book", "make a reservation", "rooms"
75
A knowledge base of entity-
oriented search intents
1. Intents searched for a type of entities

paris map, sydney map => [city] map
• (intent ID, searchedForType, entity type, confidence)
2. Categories assigned to refiners

vivienne westwood instagram => Website
vivienne westwood age => Property
vivienne westwood customer care => Service
3. Multiple refiners expressing an intent

"booking", "book", "make a reservation", "rooms"
76
A knowledge base of entity-
oriented search intents
1. Intents searched for a type of entities

paris map, sydney map => [city] map
• (intent ID, searchedForType, entity type, confidence)
2. Categories assigned to refiners

vivienne westwood instagram => Website
vivienne westwood age => Property
vivienne westwood customer care => Service
• (intent ID, ofCategory, intent category, confidence)
3. Multiple refiners expressing an intent

"booking", "book", "make a reservation", "rooms"
77
A knowledge base of entity-
oriented search intents
1. Intents searched for a type of entities

paris map, sydney map => [city] map
• (intent ID, searchedForType, entity type, confidence)
2. Categories assigned to refiners

vivienne westwood instagram => Website
vivienne westwood age => Property
vivienne westwood customer care => Service
• (intent ID, ofCategory, intent category, confidence)
3. Multiple refiners expressing an intent

"booking", "book", "make a reservation", "rooms"
• (intent ID, expressedBy, refiner, confidence)
A knowledge base of entity-
oriented search intents
78
Approach
Refiners
acquisition
Refiners
categorization
Intents
discovery
[hotel] airport

[hotel] spa

[hotel] booking

...
[hotel] airport: Service

[hotel] address: Property

[hotel] expedia: Website

...
taxi

arrive

Hotel_Arrivingbooking

make a reservation
Hotel_Booking
address
Hotel_Address
KB
construction
Intent ID Predicate Object Confidence
Hotel_Booking searchedForType [hotel] c1

Hotel_Booking ofCategory Service c2

Hotel_Booking expressedBy "booking" c3

Hotel_Booking expressedBy "make a reservation" c4
Hotel_Booking expressedBy "rooms" c5
79
Approach
Refiners
acquisition
Refiners
categorization
Intents
discovery
[hotel] airport

[hotel] spa

[hotel] booking

...
[hotel] airport: Service

[hotel] address: Property

[hotel] expedia: Website

...
taxi

arrive

Hotel_Arrivingbooking

make a reservation
Hotel_Booking
address
Hotel_Address
Intent

profile
{ KB
construction
Intent ID Predicate Object Confidence
Hotel_Booking searchedForType [hotel] c1

Hotel_Booking ofCategory Service c2

Hotel_Booking expressedBy "booking" c3

Hotel_Booking expressedBy "make a reservation" c4
Hotel_Booking expressedBy "rooms" c5
80
Knowledge base construction
• Application of the pipeline to extract all
quadruples from 581 unseen types

• 155K quadruples, 31K intent profiles

- Excerpt of the KB, for intent ID
<aviation.airline-65-customer_service>
81
Experimental evaluation
• Experts judge correctness, ignoring
confidence, of around 1.29% of IntentsKB
82
[0, 0.87) [0.87, 0.88) [0.88, 0.9) [0.9, 0.93) [0.93, 1]
Confidence intervals according to the splitting percentiles
0%
20%
40%
60%
80%
100%
Proportionoftriples
6,337 6,370 6,335 6,368 6,314
Correct
Incorrect, OFCATEGORY
Incorrect, EXPRESSEDBY
We design and build a knowledge base of entity-
oriented search intents.
We evaluate each component in our approach,
as well as the correctness of the obtained
knowledge base.
SUMMARY
83
Roadmap
Type-Aware
Entity
Retrieval
Entity-Oriented
Search
Intents
Utilizing Entity Type
Information
Identifying Target
Entity Type Information
Understanding Entity-
Oriented Search Intents
Modeling Entity-
Oriented Search Intents
84
Task-Based
Query Suggestions
An example
• Planning your wedding
86
An example
87
low wedding budget
An example
88
Cheap wedding cake
low wedding budget
An example
89
Cheap wedding cake Make your own invitations
low wedding budget
An example
90
An example
Cheap wedding cake Make your own invitations Buy a used wedding gown
low wedding budget
91
Cheap wedding
cake
Make your own invitations
Buy a used wedding gown
low wedding budget
An example
92
Cheap wedding
cake
Make your own invitations
Buy a used wedding gownExcerpt from TREC Tasks

test dataset
low wedding budget
1 low budget wedding dresses
0 low wedding budget cars
1 find a gown
...
0 wedding flowers
1 cup cake wedding
1 wedding cakes
...
2 wedding invitation
1 find wedding invitation templates
0 designer dresses wedding
...
An example
93
Cheap wedding
cake
Make your own invitations
Buy a used wedding gownExcerpt from TREC Tasks

test dataset
}
low wedding budget
1 low budget wedding dresses
0 low wedding budget cars
1 find a gown
...
0 wedding flowers
1 cup cake wedding
1 wedding cakes
...
2 wedding invitation
1 find wedding invitation templates
0 designer dresses wedding
...
An example
94
Cheap wedding
cake
Make your own invitations
Buy a used wedding gownExcerpt from TREC Tasks

test dataset
}
}
low wedding budget
1 low budget wedding dresses
0 low wedding budget cars
1 find a gown
...
0 wedding flowers
1 cup cake wedding
1 wedding cakes
...
2 wedding invitation
1 find wedding invitation templates
0 designer dresses wedding
...
An example
95
An example
Cheap wedding
cake
Make your own invitations
Buy a used wedding gownExcerpt from TREC Tasks

test dataset
}
}
}
low wedding budget
1 low budget wedding dresses
0 low wedding budget cars
1 find a gown
...
0 wedding flowers
1 cup cake wedding
1 wedding cakes
...
2 wedding invitation
1 find wedding invitation templates
0 designer dresses wedding
...
96
How can we generate query suggestions

for supporting task-based search?
97
• Given an initial query,
Suggesting queries to
support task-based search
wedding cake
wedding cake gallery
wedding cake recipes
wedding cake flavors
98
• Given an initial query,

to get a ranked list of
query suggestions
that cover all the
possible subtasks
related to the task
that the user is trying
to achieve.
Suggesting queries to
support task-based search
wedding cake
wedding cake gallery
wedding cake recipes
wedding cake flavors
99
• Given an initial query,

to get a ranked list of
query suggestions
that cover all the
possible subtasks
related to the task
that the user is trying
to achieve.
Suggesting queries to
support task-based search
wedding cake
wedding cake gallery
wedding cake recipes
wedding cake flavors
• This is the task
understanding
problem
100
Suggesting queries to
support task-based search
• We propose an end-to-end generative
probabilistic model

• We exploit different information sources
101
Suggesting queries to
support task-based search
102
Web
snippets
Web
documents
Suggesting queries to
support task-based search
103
Query suggestions
from search
engines
Suggesting queries to
support task-based search
• We propose an end-to-end generative
probabilistic model
104
• Components:
q0
Suggesting queries to
support task-based search
• We propose an end-to-end generative
probabilistic model
105
• Components:

• Source importance
q0
API SUGGS. WEB SNIPPETS WEB DOCS. WH
Suggesting queries to
support task-based search
• We propose an end-to-end generative
probabilistic model
106
• Components:

• Source importance
• Document importance
q0
API SUGGS. WEB SNIPPETS WEB DOCS. WH
Suggesting queries to
support task-based search
• We propose an end-to-end generative
probabilistic model
107
• Components:

• Source importance
• Document importance
• Keyphrase relevance
q0
Keyphrases
API SUGGS. WEB SNIPPETS WEB DOCS. WH
Suggesting queries to
support task-based search
• We propose an end-to-end generative
probabilistic model
108
• Components:

• Source importance
• Document importance
• Keyphrase relevance
• Query suggestion
• We propose an end-to-end generative
probabilistic model
Query suggestions
q0
Keyphrases
API SUGGS. WEB SNIPPETS WEB DOCS. WH
Suggesting queries to
support task-based search
109
• We make use of the 2015 and 2016 TREC
Tasks track datasets for the task understanding
problem

• We conduct a principled estimation of the
components, and analyze the best performing
estimators per component
Suggesting queries to
support task-based search
110
Suggesting queries to
support task-based search
111
• We observe a heavy reliance on query
suggestions from suggestion APIs
Generating suggestion
candidates
Query completion Query refinement
wedding cake
wedding cake gallery
wedding cake recipes
wedding cake flavors
wedding cake
beautiful wedding cakes
unique wedding cake designs
simple wedding cake
• Two query suggestion modes
112
• How to jointly generate query suggestions in
query completion and refinement modes?

- Can we do it without relying on log data / API?
• We consider a two-step pipeline:

- Candidate generation
- Candidate ranking
• And focus on the first component
Generating suggestion
candidates
113
• We study alternative generation methods and
information sources

- Methods: popular suffix, neural language, sequence-
to-sequence
- Sources: AOL query log, KnowHow, WikiAnswers
• We build a test collection of query suggestion
candidates
Generating suggestion
candidates
114
• End-to-end is still the best method overall, but
limited as it depends on API suggestions

• Log data is the most useful information source,
but the other sources provide valuable
suggestions too

• Different method-source configurations
contribute unique suggestions in both modes
Generating suggestion
candidates
115
We propose and evaluate a generative
probabilistic model for task-based query
suggestions.
We further study alternative methods and
information sources for suggestion candidate
generation, and build a test collection.
SUMMARY
116
Roadmap
Type-Aware
Entity
Retrieval
Task-Based
Search
Entity-Oriented
Search
Intents
Utilizing Entity Type
Information
Identifying Target
Entity Type Information
Understanding Entity-
Oriented Search Intents
Modeling Entity-
Oriented Search Intents
Suggesting Queries
117
Task
Recommendation
Task Recommendation
• The underlying search goal is often a complex
and knowledge-intensive task

• We propose to recommend specific tasks to
users, based on their search queries
119
An example
• Planning a wedding reception
wedding reception
Plan a wedding reception
Recommended Tasks:
Plan your wedding reception exit
Announce the bridal party at a reception
Throw a Hawaiian wedding reception
Choose wedding reception activities
120
How can we recommend tasks

based on search queries and missions?
121
Task Recommendation
• Some terminology:

- Task repository: a catalog of task
descriptions

- Task description: a semi-structured
document that explains the steps involved in
how to complete a given task

- Search mission: a set of queries that all
share the same underlying task
122
Task Recommendation
• We introduce two problems:

1. Query-based task recommendation

Given a query, to return a ranked list of tasks
that correspond to the task behind the query

2. Mission-based task recommendation

Given a search mission, to return a ranked list
of recommended tasks, corresponding to the
queries in the mission

123
Task Recommendation
• We use a
collection of
WikiHow
articles as
our task
repository
124
How to Make a Wedding Cake
Co-authored by wikiHow Staff ✔
You can make a wedding cake for a customer if you bake for a living,
or you might make a cake for loved one’s wedding to help them save
money. If you love to bake, then you might even want to make your
own wedding cake!
Steps
1 Decide on the number and shape of the cake’s layers. Consider
how many layers and what shape you want the cake to have.
2 Preheat the oven to the temperature indicated by your recipe.
Many recipes call for the oven to be pre-heated to 350 °F (177 °C).
3 Prepare the cake batter according to your recipe’s instructions.
Choose a recipe to create the cake batter for your cake.
4 Pour the batter into a greased, parchment-lined cake pan. Spray
your cake pan with non-stick cooking spray.
Explanation
Main Act
Detailed Act
Title
Task Recommendation
• We focus on a subset of tasks, the procedural
tasks

• Procedural task: a search task that can be
accomplished by following a sequence of
specific actions or subtasks
125
Task Recommendation
• From a corpus of search queries and missions,
we obtain a set of procedural search missions
126
Task Recommendation
• We build a test collection for task
recommendation
127
Query-based task
recommendation
• We propose a Learning-to-Rank method for
query-based task recommendation, that
combines a text-based ranking technique with
continuous semantic representations

• We experiment with different word embeddings
and word function sets according to POS-tag
128
129
Query-based task
recommendation
130
Query-based task
recommendation
• To address mission-based task
recommendation, we propose methods that
aggregate the individual query-based
recommendations for each query into mission-
level recommended tasks
131
Mission-based task
recommendation
132
Mission-based task
recommendation
We introduce the problems of query-based and
mission-based task recommendation.
We develop a test collection for task
recommendation, and propose and evaluate
approaches for these problems.
SUMMARY
133
Roadmap
Type-Aware
Entity
Retrieval
Task-Based
Search
Entity-Oriented
Search
Intents
Utilizing Entity Type
Information
Identifying Target
Entity Type Information
Understanding Entity-
Oriented Search Intents
Modeling Entity-
Oriented Search Intents
Suggesting Queries
Recommending Tasks
134
Conclusions
and
Future Directions
Conclusions
136
wedding cake
Stavanger
Conditori
Olja's Kake
Boutique
Gjestalveien
Conditori
Cake shops > Wedding cake shops
Recommended tasks
Make a Chocolate
Cake
Basic Chocolate
Cake
Moist & Fluffy
Chocolate Cake
Bake an Easy
Applesauce Cake
See ingredients
See steps
Address:
Gjesdalveien 27,
4306 Sandnes
Hours Today:
9AM-5PM
Address:
Godesetdalen 10,
4034 Stavanger
CALL CALL CALL
Decorate a Cake
Working with
Fondant
Adding Quick
Decorations
Queries suggested for wedding cake
wedding cake recipes for beginners
best wedding cake recipes
wedding cake recipes video
chocolate wedding cake recipes
homemade wedding cake recipes from scratch
Conclusions
137
wedding cake
Stavanger
Conditori
Olja's Kake
Boutique
Gjestalveien
Conditori
Cake shops > Wedding cake shops
Recommended tasks
Make a Chocolate
Cake
Basic Chocolate
Cake
Moist & Fluffy
Chocolate Cake
Bake an Easy
Applesauce Cake
See ingredients
See steps
Address:
Gjesdalveien 27,
4306 Sandnes
Hours Today:
9AM-5PM
Address:
Godesetdalen 10,
4034 Stavanger
CALL CALL CALL
Decorate a Cake
Working with
Fondant
Adding Quick
Decorations
Queries suggested for wedding cake
wedding cake recipes for beginners
best wedding cake recipes
wedding cake recipes video
chocolate wedding cake recipes
homemade wedding cake recipes from scratch
Type-Aware Entity Retrieval
Entity-Oriented Search Intents
Task-Based Query
Suggestions
Task
Recommendations
138
Future Directions
Future Directions
139
wedding venue
Det Stavangerske
Klubselskab 120,000 NOK
RESERVE
Olavskleivå 26
Time:
Date:
19:00
Saturday June 27, 2020
Number of
guests:
50-100
Outdoors?
Number of
cars:
Up to 20
Parking?✔
Rosenkildehuset AS
Strandkaien 6
Strømvik allotments
Strømvikveien 1
120,000 NOK
RESERVE
105,000 NOK
RESERVE
Input parameters in

service intents
Future Directions
Semantics-aware

query suggestions
Mission-based task
recommendation
140
invitation cards
Make
Homemade
Wedding Cards
Print Your Own
Wedding Invitations
Include a Dress
Code on a
Wedding
Invitation
Queries suggested for invitation cards
invitation card online
invitation card maker
free invitation cards for whatsapp
see-through invitation card
create invitation card with photo free
Recommended tasks
Thank you!

Task-Based Support in Search Engines

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    Task-Based Support in SearchEngines Darío Garigliotti University of Stavanger, Norway
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    Outline • Motivation • Type-AwareEntity Retrieval • Target Entity Type Identification • Entity-Oriented Search Intents • Task-Based Query Suggestions • Task Recommendations • Conclusions and Future Directions 2
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    Motivation • Today's websearch experience aims to understand the user query 4
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    Motivation • Today's websearch experience aims to understand the user query 5
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    Motivation • Today's websearch experience aims to understand the user query 6
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    Motivation • Today's websearch experience aims to understand the user query • A way to organize information is via structured knowledge centered around entities • Large knowledge repositories and knowledge bases have become available 7
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    • Underlying searchgoal is often a complex and knowledge-intensive task Motivation 12
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    • Underlying searchgoal is often a complex and knowledge-intensive task • For example, to plan a travel - How to get there? - Where to stay? - What to do? • Task completion would provide support for the user when accomplishing complex search tasks Motivation 15
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    An example • Searchingfor wedding cakes cake shops Konditoriet i Sandnes Olja's Kake Boutique Baker Corner Lura 18
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    An example • Searchingfor wedding cakes wedding cake shops Stavanger Conditori Olja's Kake Boutique Gjestalveien Conditori 19
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    • Entity retrievalis the task of obtaining a ranked list of entities relevant to a search query • We investigate the utilization of entity type information for entity retrieval Entity Retrieval 20
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    … Shop … …… Company Organization … Stavanger Conditori Bank LawFirm … Entity types • A characteristic property of entities is that they are typed • Types are organized in hierarchies (or taxonomies) 21
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    … Shop … …… Company Organization … cakeshopscake shops Bank Law Firm … • Target types: types of entities sought by the query Target entity types 22
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    Type-aware Entity Retrieval •Type information is known to improve entity retrieval • Yet it is a multifaceted problem query entity wedding cake shops target types Stavanger Conditori term-based similarity type-based similarity … … entity types 23
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    How can entitytype information be utilized in ad-hoc entity retrieval? 24
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    • We assumeoracle-given type information Type-aware Entity Retrieval … Shop … …… Company Organization … cake shopscake shops Bank Law Firm … 25
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    • We assumeoracle-given type information • We identify dimensions in utilizing entity type information - Type taxonomy - Type representation - Retrieval model Type-aware Entity Retrieval 26
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    • Which typetaxonomy to use? - DBpedia Ontology (7 levels, 600 types) - Freebase Types (2 levels, 2K types) - Wikipedia Categories (34 levels, 600K types) - YAGO Taxonomy (19 levels, 500K types) • These vary a lot in terms of hierarchical structure and in how entity-type assignments are recorded Type-aware Entity Retrieval 27
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    • How torepresent the hierarchical information? Type-aware Entity Retrieval 28
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    • How touse type information into entity retrieval? • Retrieval task is defined in a generative probabilistic framework P(q | e) • Both query and entity are considered in the term space as well as in the type space Type-aware Entity Retrieval 29
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    • (Strict) Filteringmodel Type-aware Entity Retrieval 30
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    • (Soft) Filteringmodel Type-aware Entity Retrieval 31
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    • We assumeoracle-given type information • We conduct an evaluation of dimensions in utilizing entity type information - Type taxonomy - Type representation - Retrieval model • We use a strong text-based baseline • We test with the DBpedia Entity collection v2 Type-aware Entity Retrieval 33
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    • Wikipedia, incombination with the most specific type representation, performs best • Hierarchical relationships from ancestor types improve retrieval effectiveness, but most specific types provide the best performance • Results regarding most effective type-aware retrieval model vary across configurations Type-aware Entity Retrieval 34
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    Target Type Identification •"We assume oracle-given type information" 37
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    Target Type Identification •"We assume oracle-given type information" 38
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    Target Type Identification •"We assume oracle-given type information" - How to identify target entity types? - How do these target types automatically identified perform for type-aware entity retrieval? 39
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    How can weautomatically identify target entity types? 40
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    Target Type Identification •We revisit the task of hierarchical target type identification • Task: to find the main target types of a query, from a type taxonomy, such that these are the most specific category of entities that are relevant to the query. If no matching type can be found in the taxonomy then the query is assigned a special NIL-type 41
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    Target Type Identification •We develop a Learning-to-Rank approach • We evaluate it using a purpose-built test collection 42
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    Target Type Identification 43 •Our method combines baseline, knowledge base, and type label features
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    • We alsoconduct an evaluation utilizing, rather than a target types oracle, target entity types automatically identified 44 Automatic types for Entity Retrieval
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    Automatic types forEntity Retrieval 45
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    We identify andevaluate dimensions in utilizing target entity type information for ad-hoc entity retrieval. We build a test collection for target entity type identification, and develop and evaluate a Learning-to-Rank approach for this problem. SUMMARY 46
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    Entity-Oriented Search Intents • Intent:the underlying user need in a entity- oriented search query - For example, the intent of booking a hotel room • Refiner: a way to express an intent in an entity-oriented query - For example, for booking a hotel room: "booking", "book", "reservation", "rooms" 49
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    • Searching abouta fashion designer An example 50
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    vivienne westwood age Anexample 78 years April 8, 1941 52
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    vivienne westwood age Anexample 78 years April 8, 1941 53
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    vivienne westwood instagram Anexample instagram.com/viviennewestwood/ 56
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    vivienne westwood instagram Anexample instagram.com/viviennewestwood/ 57
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    vivienne westwood customercare An example 59
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    vivienne westwood customercare An example 60
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    What do entity-orientedqueries ask for, and how can they be fulfilled? 61
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    <fashion designer> instagram Understandingentity- oriented search intents • We obtain a collection of type-level query patterns stella mccartney instagram vivienne westwood instagram 62
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    Understanding entity- oriented searchintents • We obtain a collection of type-level query patterns • Pick a Freebase type if it covers 100+ prominent entities • Get query suggestions for top 1000- entities per type • For each query, replace entity by type • Aggregate all frequencies for each (type, refiner) pair • Filter out all type-level refiners with frequency of 4- • Select 50 representative types by stratified sampling 63
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    Understanding entity- oriented searchintents • We define a scheme of intent categories 64
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    Understanding entity- oriented searchintents • We define a scheme of intent categories Website 65
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    Understanding entity- oriented searchintents • We define a scheme of intent categories PropertyWebsite 66
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    Understanding entity- oriented searchintents • We define a scheme of intent categories PropertyWebsite Service 67
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    Understanding entity- oriented searchintents • We define a scheme of intent categories PropertyWebsite Service Other68
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    Understanding entity- oriented searchintents • We define a scheme of intent categories - Website, Property, Service, Other => Website => Property => Service vivienne westwood age vivienne westwood instagram vivienne westwood customer care 69
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    Understanding entity- oriented searchintents • We annotate 2.3K+ unique type-level refiners with intent category via crowdsourcing • We observe the proportions of refiners in each category Property: 28.6% Service: 54.06% Website: 5.34% Other: 12.08% 70
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    Understanding entity- oriented searchintents 71 organization business operation chemical compound film location event food hotel disease restaurant travel destination 0 50 100 150 200 250 university house person newspaper airport basketball player album professional sports team game artwork 0 50 100 150 200 railway human language tv station political party amusement park exhibition venue chef programming language academic institution netflix genre 0 20 40 60 80 100 120 war currency blogger hobby football match sports championship star muscle olympic sport company 0 10 20 30 40 50 WroSicaO cycOone kingdoP PedicaO sSeciaOWy coPic book SubOisher oiO fieOd Wower beer counWry region eOecWion asWeroid beOief 0 10 20 30 40 50 3roSerWy WebsiWe Service 2Wher
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    We propose ascheme of entity-oriented search intent categories. We annotate a collection of query refiners using the scheme, and observe that there is a large proportion of service-oriented intents. SUMMARY 72
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    Roadmap Type-Aware Entity Retrieval Entity-Oriented Search Intents Utilizing Entity Type Information IdentifyingTarget Entity Type Information Understanding Entity- Oriented Search Intents 73
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    How can webuild a knowledge base of entity-oriented search intents? 74
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    1. Intents searchedfor a type of entities paris map, sydney map => [city] map 2. Categories assigned to refiners vivienne westwood instagram => Website vivienne westwood age => Property vivienne westwood customer care => Service 3. Multiple refiners expressing an intent "booking", "book", "make a reservation", "rooms" 75 A knowledge base of entity- oriented search intents
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    1. Intents searchedfor a type of entities paris map, sydney map => [city] map • (intent ID, searchedForType, entity type, confidence) 2. Categories assigned to refiners vivienne westwood instagram => Website vivienne westwood age => Property vivienne westwood customer care => Service 3. Multiple refiners expressing an intent "booking", "book", "make a reservation", "rooms" 76 A knowledge base of entity- oriented search intents
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    1. Intents searchedfor a type of entities paris map, sydney map => [city] map • (intent ID, searchedForType, entity type, confidence) 2. Categories assigned to refiners vivienne westwood instagram => Website vivienne westwood age => Property vivienne westwood customer care => Service • (intent ID, ofCategory, intent category, confidence) 3. Multiple refiners expressing an intent "booking", "book", "make a reservation", "rooms" 77 A knowledge base of entity- oriented search intents
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    1. Intents searchedfor a type of entities paris map, sydney map => [city] map • (intent ID, searchedForType, entity type, confidence) 2. Categories assigned to refiners vivienne westwood instagram => Website vivienne westwood age => Property vivienne westwood customer care => Service • (intent ID, ofCategory, intent category, confidence) 3. Multiple refiners expressing an intent "booking", "book", "make a reservation", "rooms" • (intent ID, expressedBy, refiner, confidence) A knowledge base of entity- oriented search intents 78
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    Approach Refiners acquisition Refiners categorization Intents discovery [hotel] airport [hotel] spa [hotel]booking ... [hotel] airport: Service [hotel] address: Property [hotel] expedia: Website ... taxi arrive Hotel_Arrivingbooking make a reservation Hotel_Booking address Hotel_Address KB construction Intent ID Predicate Object Confidence Hotel_Booking searchedForType [hotel] c1 Hotel_Booking ofCategory Service c2 Hotel_Booking expressedBy "booking" c3 Hotel_Booking expressedBy "make a reservation" c4 Hotel_Booking expressedBy "rooms" c5 79
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    Approach Refiners acquisition Refiners categorization Intents discovery [hotel] airport [hotel] spa [hotel]booking ... [hotel] airport: Service [hotel] address: Property [hotel] expedia: Website ... taxi arrive Hotel_Arrivingbooking make a reservation Hotel_Booking address Hotel_Address Intent profile { KB construction Intent ID Predicate Object Confidence Hotel_Booking searchedForType [hotel] c1 Hotel_Booking ofCategory Service c2 Hotel_Booking expressedBy "booking" c3 Hotel_Booking expressedBy "make a reservation" c4 Hotel_Booking expressedBy "rooms" c5 80
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    Knowledge base construction •Application of the pipeline to extract all quadruples from 581 unseen types • 155K quadruples, 31K intent profiles - Excerpt of the KB, for intent ID <aviation.airline-65-customer_service> 81
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    Experimental evaluation • Expertsjudge correctness, ignoring confidence, of around 1.29% of IntentsKB 82 [0, 0.87) [0.87, 0.88) [0.88, 0.9) [0.9, 0.93) [0.93, 1] Confidence intervals according to the splitting percentiles 0% 20% 40% 60% 80% 100% Proportionoftriples 6,337 6,370 6,335 6,368 6,314 Correct Incorrect, OFCATEGORY Incorrect, EXPRESSEDBY
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    We design andbuild a knowledge base of entity- oriented search intents. We evaluate each component in our approach, as well as the correctness of the obtained knowledge base. SUMMARY 83
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    Roadmap Type-Aware Entity Retrieval Entity-Oriented Search Intents Utilizing Entity Type Information IdentifyingTarget Entity Type Information Understanding Entity- Oriented Search Intents Modeling Entity- Oriented Search Intents 84
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    An example • Planningyour wedding 86
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    Cheap wedding cake lowwedding budget An example 89
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    Cheap wedding cakeMake your own invitations low wedding budget An example 90
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    An example Cheap weddingcake Make your own invitations Buy a used wedding gown low wedding budget 91
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    Cheap wedding cake Make yourown invitations Buy a used wedding gown low wedding budget An example 92
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    Cheap wedding cake Make yourown invitations Buy a used wedding gownExcerpt from TREC Tasks test dataset low wedding budget 1 low budget wedding dresses 0 low wedding budget cars 1 find a gown ... 0 wedding flowers 1 cup cake wedding 1 wedding cakes ... 2 wedding invitation 1 find wedding invitation templates 0 designer dresses wedding ... An example 93
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    Cheap wedding cake Make yourown invitations Buy a used wedding gownExcerpt from TREC Tasks test dataset } low wedding budget 1 low budget wedding dresses 0 low wedding budget cars 1 find a gown ... 0 wedding flowers 1 cup cake wedding 1 wedding cakes ... 2 wedding invitation 1 find wedding invitation templates 0 designer dresses wedding ... An example 94
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    Cheap wedding cake Make yourown invitations Buy a used wedding gownExcerpt from TREC Tasks test dataset } } low wedding budget 1 low budget wedding dresses 0 low wedding budget cars 1 find a gown ... 0 wedding flowers 1 cup cake wedding 1 wedding cakes ... 2 wedding invitation 1 find wedding invitation templates 0 designer dresses wedding ... An example 95
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    An example Cheap wedding cake Makeyour own invitations Buy a used wedding gownExcerpt from TREC Tasks test dataset } } } low wedding budget 1 low budget wedding dresses 0 low wedding budget cars 1 find a gown ... 0 wedding flowers 1 cup cake wedding 1 wedding cakes ... 2 wedding invitation 1 find wedding invitation templates 0 designer dresses wedding ... 96
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    How can wegenerate query suggestions for supporting task-based search? 97
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    • Given aninitial query, Suggesting queries to support task-based search wedding cake wedding cake gallery wedding cake recipes wedding cake flavors 98
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    • Given aninitial query, to get a ranked list of query suggestions that cover all the possible subtasks related to the task that the user is trying to achieve. Suggesting queries to support task-based search wedding cake wedding cake gallery wedding cake recipes wedding cake flavors 99
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    • Given aninitial query, to get a ranked list of query suggestions that cover all the possible subtasks related to the task that the user is trying to achieve. Suggesting queries to support task-based search wedding cake wedding cake gallery wedding cake recipes wedding cake flavors • This is the task understanding problem 100
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    Suggesting queries to supporttask-based search • We propose an end-to-end generative probabilistic model • We exploit different information sources 101
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    Suggesting queries to supporttask-based search 102 Web snippets Web documents
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    Suggesting queries to supporttask-based search 103 Query suggestions from search engines
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    Suggesting queries to supporttask-based search • We propose an end-to-end generative probabilistic model 104
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    • Components: q0 Suggesting queriesto support task-based search • We propose an end-to-end generative probabilistic model 105
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    • Components: • Sourceimportance q0 API SUGGS. WEB SNIPPETS WEB DOCS. WH Suggesting queries to support task-based search • We propose an end-to-end generative probabilistic model 106
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    • Components: • Sourceimportance • Document importance q0 API SUGGS. WEB SNIPPETS WEB DOCS. WH Suggesting queries to support task-based search • We propose an end-to-end generative probabilistic model 107
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    • Components: • Sourceimportance • Document importance • Keyphrase relevance q0 Keyphrases API SUGGS. WEB SNIPPETS WEB DOCS. WH Suggesting queries to support task-based search • We propose an end-to-end generative probabilistic model 108
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    • Components: • Sourceimportance • Document importance • Keyphrase relevance • Query suggestion • We propose an end-to-end generative probabilistic model Query suggestions q0 Keyphrases API SUGGS. WEB SNIPPETS WEB DOCS. WH Suggesting queries to support task-based search 109
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    • We makeuse of the 2015 and 2016 TREC Tasks track datasets for the task understanding problem • We conduct a principled estimation of the components, and analyze the best performing estimators per component Suggesting queries to support task-based search 110
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    Suggesting queries to supporttask-based search 111 • We observe a heavy reliance on query suggestions from suggestion APIs
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    Generating suggestion candidates Query completionQuery refinement wedding cake wedding cake gallery wedding cake recipes wedding cake flavors wedding cake beautiful wedding cakes unique wedding cake designs simple wedding cake • Two query suggestion modes 112
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    • How tojointly generate query suggestions in query completion and refinement modes? - Can we do it without relying on log data / API? • We consider a two-step pipeline: - Candidate generation - Candidate ranking • And focus on the first component Generating suggestion candidates 113
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    • We studyalternative generation methods and information sources - Methods: popular suffix, neural language, sequence- to-sequence - Sources: AOL query log, KnowHow, WikiAnswers • We build a test collection of query suggestion candidates Generating suggestion candidates 114
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    • End-to-end isstill the best method overall, but limited as it depends on API suggestions • Log data is the most useful information source, but the other sources provide valuable suggestions too • Different method-source configurations contribute unique suggestions in both modes Generating suggestion candidates 115
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    We propose andevaluate a generative probabilistic model for task-based query suggestions. We further study alternative methods and information sources for suggestion candidate generation, and build a test collection. SUMMARY 116
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    Roadmap Type-Aware Entity Retrieval Task-Based Search Entity-Oriented Search Intents Utilizing Entity Type Information IdentifyingTarget Entity Type Information Understanding Entity- Oriented Search Intents Modeling Entity- Oriented Search Intents Suggesting Queries 117
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    Task Recommendation • Theunderlying search goal is often a complex and knowledge-intensive task • We propose to recommend specific tasks to users, based on their search queries 119
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    An example • Planninga wedding reception wedding reception Plan a wedding reception Recommended Tasks: Plan your wedding reception exit Announce the bridal party at a reception Throw a Hawaiian wedding reception Choose wedding reception activities 120
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    How can werecommend tasks based on search queries and missions? 121
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    Task Recommendation • Someterminology: - Task repository: a catalog of task descriptions - Task description: a semi-structured document that explains the steps involved in how to complete a given task - Search mission: a set of queries that all share the same underlying task 122
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    Task Recommendation • Weintroduce two problems: 1. Query-based task recommendation Given a query, to return a ranked list of tasks that correspond to the task behind the query 2. Mission-based task recommendation Given a search mission, to return a ranked list of recommended tasks, corresponding to the queries in the mission 123
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    Task Recommendation • Weuse a collection of WikiHow articles as our task repository 124 How to Make a Wedding Cake Co-authored by wikiHow Staff ✔ You can make a wedding cake for a customer if you bake for a living, or you might make a cake for loved one’s wedding to help them save money. If you love to bake, then you might even want to make your own wedding cake! Steps 1 Decide on the number and shape of the cake’s layers. Consider how many layers and what shape you want the cake to have. 2 Preheat the oven to the temperature indicated by your recipe. Many recipes call for the oven to be pre-heated to 350 °F (177 °C). 3 Prepare the cake batter according to your recipe’s instructions. Choose a recipe to create the cake batter for your cake. 4 Pour the batter into a greased, parchment-lined cake pan. Spray your cake pan with non-stick cooking spray. Explanation Main Act Detailed Act Title
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    Task Recommendation • Wefocus on a subset of tasks, the procedural tasks • Procedural task: a search task that can be accomplished by following a sequence of specific actions or subtasks 125
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    Task Recommendation • Froma corpus of search queries and missions, we obtain a set of procedural search missions 126
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    Task Recommendation • Webuild a test collection for task recommendation 127
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    Query-based task recommendation • Wepropose a Learning-to-Rank method for query-based task recommendation, that combines a text-based ranking technique with continuous semantic representations • We experiment with different word embeddings and word function sets according to POS-tag 128
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    • To addressmission-based task recommendation, we propose methods that aggregate the individual query-based recommendations for each query into mission- level recommended tasks 131 Mission-based task recommendation
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    We introduce theproblems of query-based and mission-based task recommendation. We develop a test collection for task recommendation, and propose and evaluate approaches for these problems. SUMMARY 133
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    Roadmap Type-Aware Entity Retrieval Task-Based Search Entity-Oriented Search Intents Utilizing Entity Type Information IdentifyingTarget Entity Type Information Understanding Entity- Oriented Search Intents Modeling Entity- Oriented Search Intents Suggesting Queries Recommending Tasks 134
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    Conclusions 136 wedding cake Stavanger Conditori Olja's Kake Boutique Gjestalveien Conditori Cakeshops > Wedding cake shops Recommended tasks Make a Chocolate Cake Basic Chocolate Cake Moist & Fluffy Chocolate Cake Bake an Easy Applesauce Cake See ingredients See steps Address: Gjesdalveien 27, 4306 Sandnes Hours Today: 9AM-5PM Address: Godesetdalen 10, 4034 Stavanger CALL CALL CALL Decorate a Cake Working with Fondant Adding Quick Decorations Queries suggested for wedding cake wedding cake recipes for beginners best wedding cake recipes wedding cake recipes video chocolate wedding cake recipes homemade wedding cake recipes from scratch
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    Conclusions 137 wedding cake Stavanger Conditori Olja's Kake Boutique Gjestalveien Conditori Cakeshops > Wedding cake shops Recommended tasks Make a Chocolate Cake Basic Chocolate Cake Moist & Fluffy Chocolate Cake Bake an Easy Applesauce Cake See ingredients See steps Address: Gjesdalveien 27, 4306 Sandnes Hours Today: 9AM-5PM Address: Godesetdalen 10, 4034 Stavanger CALL CALL CALL Decorate a Cake Working with Fondant Adding Quick Decorations Queries suggested for wedding cake wedding cake recipes for beginners best wedding cake recipes wedding cake recipes video chocolate wedding cake recipes homemade wedding cake recipes from scratch Type-Aware Entity Retrieval Entity-Oriented Search Intents Task-Based Query Suggestions Task Recommendations
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    Future Directions 139 wedding venue DetStavangerske Klubselskab 120,000 NOK RESERVE Olavskleivå 26 Time: Date: 19:00 Saturday June 27, 2020 Number of guests: 50-100 Outdoors? Number of cars: Up to 20 Parking?✔ Rosenkildehuset AS Strandkaien 6 Strømvik allotments Strømvikveien 1 120,000 NOK RESERVE 105,000 NOK RESERVE Input parameters in service intents
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    Future Directions Semantics-aware query suggestions Mission-basedtask recommendation 140 invitation cards Make Homemade Wedding Cards Print Your Own Wedding Invitations Include a Dress Code on a Wedding Invitation Queries suggested for invitation cards invitation card online invitation card maker free invitation cards for whatsapp see-through invitation card create invitation card with photo free Recommended tasks
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