Hugh E. WilliamsVice President, Experience, Search, and Platforms@hughewilliams, hugh@hughwilliams.com

Challenges in Commerce Search

eBay Today

Of data in our Hadoop and Teradata clusters

Page views each day

Database calls each day

50+ petabytes

2+ billion

75+ billion

250 million Queries per day

$1 trillion

Commerce

$10 trillionThe opportunity ahead is huge

Source: Economist Intelligence Unit, Morgan StanleyNote: Market sizes as of 2012, Compounded Annual Growth Rates from 2012 to 2015

Online Commerce

Today’s Search

Turnaround contributor

Series of improvements

Ten year old technology

Series1

Conversion up 13%

Better Search

2010 Simple Flows

Better Images

Merch’ing Other 2012

Improving Search from 2009 to 2012

– User experience changes• Imagery• Reorganization• Optimization• Major page refresh• Speed

– Search science• Query understanding and rewriting• Understanding user intent• Behavioral measurement• Substantial ranking improvements (particularly to Fixed Price ranking)

– And all on a 10+ year old platform named Voyager

Query Understanding and Rewriting

•Our search engine was literal•We’re on a journey to make it more intuitive•Idea: Mine our query-session data, look for patterns, and use these to map words in user queries to synonyms and structured data

Query RewriteSearch

User Query

eBay Results

Search Query

PATTERNS: QUERY REWRITES …

pilzlampe

How do buyers purchase the pilzlampe?

•It turns out, they do one of a few things:–Type pilzlampe, and purchase–Type pilzlampe, … , pilz lampe, and purchase–Type pilzlampe, … , pilzlampen, and purchase–Type pilz lampen, … , pilzlampe, and purchase–…

How do buyers purchase the pilzlampe?

•From our data mining:–We automatically discover that pilz lampe and pilzlampe are the

same–We also discover that pilz and pilze are the same, and lampe and

lampen are the same•From these patterns, we rewrite the user’s query pilzlampe as:

pilzlampe OR “pilz lampe” OR “pilz lampen” OR pilzlampen OR “pilze lampe” OR pilzelampe OR “pilze lampen” OR pilzelampen

Are Query Rewrites easy?

• Nothing is easy at scale– Incorrect strong signals:

• CMU is not Central Michigan University• Mariners is not the same as Marines

– Context matters• Correcting Seattle Marines to Seattle Mariners is (generally) right• Denver Nuggets is not Denver in the Jewelry & Watches category

An even bigger opportunity

Next Gen Search

Cassini: Reengineering eBay Search

Top-to-Bottom View

How hard is it to ship a new search engine?

• Voyager is used for much more than the obvious. It’s multi-tenant:– “Default Search” search (already migrated to Cassini in the US)– Completed, null and low (already migrated to Cassini worldwide)– Description search– Deterministic sorts– Query rewrite– Merchandizing– The Feed– Selling (for example, allowing sellers to create listings from similar items)– Category browsing– Motors and other verticals– Many fast “item lookup” scenarios for other teams– Many scenarios we don’t even know about…

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What’s else is hard about eBay search?• eBay has over 400 million items listed in multiple languages• Our collection of items changes fast• You can find just about anything on eBay. We have to optimize for every type of item• Not everybody follows the same listing practices, or uses the same keywords or units

– Examples include:• Units of measure: centimeter versus cm, gigabytes versus gb• Colors: Blue versus Aqua, Rojo is the same as Red• Synonyms: laptop and notebook, mobile phone and cell phone• Abbreviations: SGA means Stadium Giveaway• Spelling errors

• Our goal is to help both buyers and sellers find items even when they use different ways of expressing the same things

Technology Deep dive: Infrastructure

• What’s hard at eBay?– Multi-tenant system– Document additions and deletions– Document modifications– Index updates– Result caching– Data center automation–…

Technology Deep dive: Ranking

• What’s hard at eBay?–Mix of items: good ’til canceled multi quantity vs. single quantity–Gaps in catalog data–A very different problem: different ranking signals to Web search–The deterministic sort:

• Recall versus precision• Consistency with best match

–Spam–Result blending

But What Comes Next?

21%of eBay multiscreenusers

44% of GMV share

Q&A?