fountain of youth or polluted swamp: is your data lake revitalizing your business or eroding the...

11 ZILLOW | TRULIA | STREETEASY | HOTPADS | NAKED APARTMENTS

Vincent Yates, Director of Analytics Engineering@VincentYates8

FOUNTAIN OF YOUTH OR POLLUTED SWAMP: IS YOUR DATA LAKE REVITALIZING YOUR BUSINESS OR ERODING THE FOUNDATION?

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One of these is worth $42,000 more

Finished sq-ft 2,602 2,602Lot Size 4,400 5,342Bathrooms 3 3Bedrooms 4 4Year Built 2004 2005Sale Price 861,000 819,000

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One of these is worth $164,000 more

Finished sq-ft 1,620 1,620Lot Size 1,620 1,620Bathrooms 2.5 3Bedrooms 3 3Year Built 2007 2007Sale Price 499,000 663,000

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One of these is worth >$10M annually

http://www.exp-platform.com/Pages/SevenRulesofThumbforWebSiteExperimenters.aspx

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DATA SCIENCE’S DIRTY LITTLE SECRET

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$3.1 TRILLION

IBM Big Data Hub

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Unknowns ≠ Seasonality

Seasonality

Seasonality

Seasonality

Seasonality

SeasonalitySeasonality

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SeriouslyDATA SCIENCE IS HARD

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Product &Communication

Programming

Statistics

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24% of data scientists

UNSURE OF HOW MUCH OF THEIR DATA ARE INACCURATE

IBM Big Data Hub

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Errors Propagate in Dynamic Ways

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66% of data scientists

CLEANING DATA IS THE MOST TIME CONSUMING TASK

CroundFlower 2015 Data Science Report

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My data is pretty good.DOES IT REALLY MATTER?

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52.3% of data scientists

POOR DATA QUALITY IS THEIR BIGGEST HURDLE

CroundFlower 2015 Data Science Report

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The cost of poor data quality

15-25% OF OPERATING PROFIT

Kaufman,Morgan: The Accuracy Dimension

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Someone would have noticed and fixed itHOW DID WE GET HERE?

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Cracks start to show under pressure

Data Quality: The Accuracy DimensionThe Morgan Kaufmann Series in Data Management Systems

OperationalIntegration Replication

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Complexity/Agility is the scapegoat

Transaction applications,APIs, Third-party data producers

Transaction databases

Data Marts

Data Lake

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Complexity/Agility is the scapegoat

Transaction applications,APIs, Third-party data producers

Transaction databases

Data Marts

Data Lake

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Complexity/Agility is the scapegoat

Transaction applications,APIs, Third-party data producers

Transaction databases

Data Marts

Data Lake

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Complexity/Agility is the scapegoat

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Complexity/Agility is the scapegoat

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Complexity/Agility is the scapegoatData Marts

Data Lake

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Moral Hazard is the culprit

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HOW DO WE GET OUT?A few simple tricks to head in the right direction

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PROACTIVE NOT REACTIVEData scientist is not great under duress

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Get Back to Raw Data

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Centralize Definitions

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Model Where Possible

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MODELING IS HARDBuild tools to make reactive easier

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Data Problems are as Old as Data

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Many mistakes are required for catastrophe• Climate caused more icebergs

– Ignored Forecasts

• Tides sent icebergs southward– Poor/Wrong Measurement

• The ship was going too fast– Business needs over best data

• Iceberg warnings went unheeded– Data was Disregarded for Intuition

• The binoculars were locked up– Tools were behind lock and key

• The steersman took a wrong turn– Reactive action under stress lead to

wrong decisions

• The iron rivets were too weak– Cost savings over best data

• There were too few lifeboats– Marketing owned the message

http://cosmiclog.nbcnews.com/_news/2012/04/01/10970732-10-causes-of-the-titanic-tragedy

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VincentYa@zillowgroup.com@VincentYates8

THANK YOU!