1. OSM ERROR MANAGEMENT
SOTM Portland 2012

2. INTRODUCTION
• John Novak
• Principal Map Engineer, Telenav (8/12)
• Sr Software Engineer, MapQuest (10/10 – 7/12)
• Architect, Telenav (10/08 – 10/10)
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3. TELENAV LOCATION
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4. TELENAV LOCATION
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5. TELENAV LOCATION
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6. OVERVIEW
• OSM Data Quality
– Assessment
– Trending
– Improvement Strategy
– Lessons Learned
– Results
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7. QUALITY ASSESSMENT
• Just how good is the data
– Quality Checks
• External Tools (OSMI, Keepright,…)
• SQL Scripts
• Applications
• Multiple Data Sources
– Example Error Classes
• Simple Connectivity
• Partial Way Overlaps
• Isolated Ways (just added to OSMI ROE as islands)
• Routing
• GeoCoding
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8. QUALITY TRENDING
• Given the existence of errors, how quickly are they
being addressed ?
• How does OSM quality today compare with OSM
quality pre-redaction ?
• How to prevent (or at least detect) significant quality
regression
– Vandalism, for example
– Challenging
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9. PRE/POST REDACTION LINKS
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10. PRE/POST REDACTION LINKS
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11. PRE/POST REDACTION CONNECTIVITY
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12. PRE/POST REDACTION CONNECTIVITY
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13. IMPROVEMENT STRATEGY
• Two Tracks
– Technology (Top-Down)
– Telenav Community (Bottom-Up)
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14. TECH
• Technology (Top-Down)
– Leverage map expertise and internal data for detection
– Identify errors such as
• Direction of Flow
• Grade Separation
• Turn Restrictions
– Using internally developed application suite
– Publish to OSM community
– Leverage existing tools (such as OSMI)
– Targeting 24 hour update cycle
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15. TELENAV COMMUNITY
• Telenav Community (Bottom-Up)
– Significant proportion of new editors
– Training
– Edit-a-thon Sessions
– Focus on “simple” errors first
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16. LESSONS LEARNED
• “Simple” errors can rapidly become not so simple
– Partial Way overlaps
– Multiple copies of ways (in some cases, a dozen)
– Navigable ways merged with boundaries and areas
– Allow error bypass
• Epic Tediousity
– The simple is also really boring
– Feedback on progress
– Bite-sized chunks
– Stats
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17. EXAMPLE
• Simple connectivity fixes
• Focus on county boundaries
• About 2.5 months elapsed time
• Approx 350 person hours
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18. OSM US WAY CONNECTIVITY (OSMI 8/23/12)
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19. OSM US WAY CONNECTIVITY (TNAV 10/12/12)
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20. OSM US WAY CONNECTIVITY (TNAV 10/12/12)
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21. MENLO PARK CA ADDRESS POINTS
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22. CLOSING REMARKS
• Generate error status updates as quickly as possible
• Staleness blunts momentum (tighten the loop)
• Guidance on what and where to apply effort
• Provide alternatives
• It does not take long to effect major improvements
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23. QUESTIONS
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