Reviewing labelled and predicted changesets from feature classifier

[bkowshik]

With results from https://github.com/mapbox/gabbar/issues/43, I plan to review 15 changesets in each of the following categories:

• Labelled problematic and predicted problematic
• Labelled problematic and predicted good
• Labelled good and predicted good
• Labelled good and predicted problematic

[bkowshik]

Labelled problematic and predicted problematic

Duplicate looking tags

• One of the attributes used for training was the number of duplicate looking tags in the feature
• The idea was to flag features with landuse, landuse_1, etc
• Not every duplicate looking tag is a 👎 though.
• Good tags to have
  • building, building:level, etc
  • addr, addr:city, etc
• Not so good to have
  • landuse, landuse_1, ...
  • surface, surface_1, ...

Users with blocks

• A feature gets an old_name=Порт-Артура in https://osmcha.mapbox.com/44818408/
• But, this might not be problematic as is without the larger context of user having a user block
• User block: http://www.openstreetmap.org/user_blocks/1147
• The user does start using old_name tag, but still is part of the giant reverted
• Model don't have the additional context of the user block

Adding leisure=park

• We have seen lots of activity around converting existing features to parks.
• This should totally be part of our Regression Test Suite

Personal information

• Often, mappers add some personal information onto OSM
• Feature names could have things like home, My friend's place, etc
• Ex: https://osmcha.mapbox.com/46374766/

[bkowshik]

Labelled problematic and predicted good

Additional context

• Sometimes, where the feature is on the map is crucial to understand the feature
• In https://osmcha.mapbox.com/47898163/, a highway=footway is good as is
• But, when we add environment the feature is in, we see there already exists a highway=footway
• Similarly, in https://osmcha.mapbox.com/46383265/ we need to know about the existence of a similar feature nearby, a hospital with the same name in this case.
• A park with same name nearby: https://osmcha.mapbox.com/47051957/

Impossible tags

• There are some features and should not have some tags.
• Ex: The node Paris gets a shop=bicycle in https://osmcha.mapbox.com/46978170/
• Note: Value for name:en=France is inappropriate too

[bkowshik]

Labelled good and predicted good

Name translations

• The model currently is making a guess when there is a name translation
• Ex: In https://osmcha.mapbox.com/48119284/, name:en=Chalcis was added
• The only related attributes the model gets are feature_name_translation_new_version=8 and feature_name_translation_old_version=7

Wikidata

• There are inherent properties about every tag and value. Ex: Every Wikidata tag should start with a Q? Ex: Q6529766
• In https://osmcha.mapbox.com/48448760/, the Wikidata tag has the value of Wikipedia ru:Церковь_Святого_Филиппа_(Ташкент)

General to specific

• When a value goes from a general value to a more specific value, it mostly is a good thing
• Ex: in https://osmcha.mapbox.com/48044675/, we go from building=yes -> building=school

[bkowshik]

Labelled good and predicted problematic

Pure geometry modifications

• Looks like the model does not have enough information to make this decision
• A majority of features we currently have for the model are property based
• The attributes that come close to being relevant are:
  • feature_area and feature_area_old: Since the feature is a node have a value of 0
  • The values for leisure and sport remain unchanged so might not be very useful
• We definitely need more geometry based attributes. Ex:
  • Distance between new version and old version of feature
  • Number of nodes in the feature

Feature name

• If the value of name tag does not have any profanity, it should mostly be good.
• Percentage of name modification could a feature we could explore. Ex:
  • Levenshtein distance based scores.
  • In, https://osmcha.mapbox.com/46823062/, the distance between value of name tag is 8
  • Could be useful here as well: https://osmcha.mapbox.com/46987866/

Redundant tags

• There are tags that are reference only and do not contribute similarly to other properties
• In https://osmcha.mapbox.com/47919135/, the feature gets a description.
• Skip checking such tags could be a wise thing to do at the current state of the project

[bkowshik]

No next actions here. Closing.