Searching the Social WebThe Challenges of Socially-Connected Search

IR Leadership Seminar 2008 / Ofer Egozi

The The problem…problem…

What to choose?Whom to trust??...

…

The solution?The solution?

What to choose?Whom to trust??...

The solution?The solution?

Socially- Socially- connected connected search:search:• Leveraging the Social

Graph in web search▫ Focused crawling▫ Personalized ranking

• Delver is a first-mover

What to choose?Who to trust??...

The solution?The solution?

Socially- Socially- connected connected search:search:• Trusted results

▫ Friends qualify content/sources▫ Potential contact in reach▫ Spam is inherently low

• Reasoning over results▫ Ranking is transparent▫ Easier to assess relevance

• Network discovery▫ Experts in my network▫ Serendipity

What to choose?Who to trust??...

Outline

•Approaches to Social Search•The Social Graph•Graph-Related Challenges•Search-Related Challenges

Humans in the loop

•Search = crawl + index + rank + query

•Crawling (Dmoz, Mahalo)•Indexing (del.icio.us, Flickr)•Querying (ChaCha)•Ranking – that’s what we’ll discuss…

A Taxonomy of Social Search

Aggregated

Personalized

Network-based

Behavior-based

?

?

The Social Graph

•A directed, cyclic graph▫ Nodes are people (identities)▫ Edges are relations between them

•Large portion is public on social networks•A lot isn’t – cellular, email, non-digital

•Emerging web standards▫ OpenID/hCard – identifier/identity▫ Contact APIs/PoCo/XFN – private/public contact lists▫ FB Connect – a full proprietary framework

Social Graph in Research

•Extraction from interactions▫ Email (Van Alstyne et al. 2003), Chat (Tuulos & Tirri 2004), IM (Lang

2004)

•Correlation with “physical”▫ Bluetooth contact (Mtibaa et al. 2008)

•Security and Privacy▫ Shared knowledge authentication (Toomim et al. 2008)▫ Graph link privacy (Xu 2008), (Korolova et al. 2008)

•Enhance IR ranking▫ Index friends browse history (Mislove et al. 2006)▫ Rank by author centrality (Kirchhoff et al. 2008)▫ Rerank by sampling network click-log (Das et al. 2008)

So first we need to draw the graph…

Social Graph - challenges

•Social graph nodes▫ Identities/relations across networks

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Joe

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•Social graph nodes▫ Identities/relations across networks▫ Identity impersonation▫ Non-individual identities (groups,

shared authorship…)▫ Privacy is an issue, even with public data

•Social graph edges▫ Relation “strength” not exposed▫ Super nodes may dominate results▫ “Politeness” relations are not filtered out▫ Automatic generation – double-edged sword

Social Graph - challengesJoe

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friend-of

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Joe

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So now we’ve mapped the social graph…

…and attached each node with its content…

…can we finally go fetch?

S-C Search - challenges

•Must build a search engine…▫Store graph, attach content to nodes▫Reranking will not do, this is the long tail

Not in Google’s / Yahoo!’s top-1000!…(dominated by authorities)

S-C Search - challenges

•Must build a search engine…▫Store graph, attach content to nodes▫Reranking will not do, this is the long tail▫Scale well, including graph functions

•Personalized graph-based rank▫Integrate content-based with static ranking▫Use web graph structure, like PageRank etc.▫Network is egocentric, unlike PageRank

Socially-Connected Search

• What are the enablers? ▫Social networks▫Users’ content boom

• What can be achieved?▫Search-based access to network content▫Trusted and transparent social ranking

• What are the challenges?▫Fragmented social graph▫Personal-network ranking

Thank you!http://

www.delver.com

Thank you!http://

www.delver.com