Tag: Stats

Review requests of OpenStreetMap contributors
– How you can assist! –

The latest version of the OpenStreetMap editor iD has a new feature: “Allow user to request feedback when saving“. This idea has been mentioned in a diary post by Joost Schouppe about “Building local mapping communities” (at that time: “#pleasereview”) in 2016. The blog post also contains some other additional and good thoughts, definitely worth reading.

However, based on the newly implemented feature, any contributor can flag her/his changeset and ask for feedback. Now it’s your turn! How can you find and support those OSM’ers?

  • Step 1: Based on the “Find Suspicious OpenStreetMap Changesets” page you can search for flagged changesets, e.g. limited to your country only: Germany or UK.
  • Step 2: Leave a changeset comment where you e.g. welcome the contributor and (if necessary) give her/him some feedback about the map changes. You could also add some additional information, such as links to wiki pages of tags (map features), good mapping practices, the OSM forum, OSM help or mailing lists. Based on the changeset comment other contributors can see that the original contributor of this changeset already has been provided with some feedback.
  • Step 3: Finally you could create & save a feed URL of your changeset’s search. That’s it.

Personally, I really like this new feature. It provides an easy way to search for contributors who are asking for feedback about their map edits. Thanks to all iD developer’s for implementing this idea. What do you think? Should I add an extra score to “How did you contribute to OpenStreetMap” where every answer to a requested feedback changeset will be counted?

Some statistics? There you go: “OSM Changesets of the last 30 Days

Thanks to maɪˈæmɪ Dennis.

Who is commenting?
An Overview about OSM Changeset Discussions

As mentioned in my previous blog post about detecting vandalism in OpenStreetMap (OSM) edits, it’s highly recommended that contributors use public changeset discussions when contacting other mappers regarding their edits. This feature was introduced at the end of 2014 and is used widely by contributors today. Each and every comment is listed publicly and every contributor can read the communication and, if necessary, add further comments or thoughts. In most cases where questions about a specific map edit come up, it is desirable that contributors take this route of communication instead of private messaging each other.

For my presentation at the German FOSSGIS & OpenStreetMap conference I created several statistics about the aforementioned changeset discussion feature. For this blog post I reran all analyses and created some new charts and statistics. Let’s start with the first image (above): It shows the number of commented or discussed changesets per month since its introduction. The peak in January, 2017 is based on a revert with several thousands of changesets.

In total, more than 92,000 changesets have been discussed in the past few years with around 151,000 comments. All comments were created by almost 14,000 different contributors. So far most changesets were commented in Germany, the United States, Russia and the UK, as you can see in the following images. This correlates to some extent, with the exception of Kazakstan, with the number of active contributors for each country (see e.g. OSMstats for active contributors). As shown on the right side, many changesets (71%) only received one comment or discussion. This means, in most cases the commented changeset did not receive a response by the owner/contributor of the changeset.

Which changesets are discussed and who creates comments? I think it’s not surprising to see that most changesets by new contributors receive a comment. However, as the following charts show, there are also changesets by long-time contributors that have some discussions. It’s also quite interesting to see that all kinds of contributors (new and long-time) created discussions. I would have expected a trend towards contributors with a higher number of mapping days.

What is the origin of the contributor who created the comment? Again, not surprisingly, this correlates with the number of active OSM contributors per country as mentioned above. The contributors’ origin is determined by his/her main activity areas which you can find/see on “How did you contribute to OpenStreetMap?“.

Some additional numbers about the text content of the changeset discussions: Roughly 22% of the changeset comments contain the word “revert”. On the other side, more than 17% include some sort of “Welcome”, “Willkommen”, “Hello”, “Ciao”, “Hola”, “Bonjour”, “nǐ hǎo!” or “привет!” text. The following image shows a word cloud of the most used words in the changeset discussions:

The last chart shows the accumulative changeset discussion contributors and comments. Almost 63% of all discussion comments have been created by around 2% of the contributors. However, I assume this looks very similar to other long tails of OpenStreetMap contribution charts. What do you think?

Want to see the latest OSM discussions in your area or country? Check this webpage.

Thanks to maɪˈæmɪ Dennis.

A comparative study between different OpenStreetMap contributor groups – Outline 2016

Over the past few years I have written several blog posts about the (non-) activity of newly registered OpenStreetMap (OSM) members (2015, 2014, 2013). Similarly to the previous posts, the following image shows the gap between the number of registered and the number of active OSM members. Although the project still shows millions of new registrations, “only” several hundred thousand of these registrants actually edited at least one object. Simon showed similar results in his yearly changeset studies.

2016members

The following image shows, that the project still has some loyal contributors. More specifically, it shows the increase in monthly active members over the past few years and their consistent data contributions based on the first and latest changeset:

2016months

However, this time I would like to combine the current study with some additional research. I tried to identify three different OSM contributor groups, based on the hashtag in a contributor’s comment or the utilized editor, for the following analysis:

  1. Contributors of the MissingMaps-Project: A contributors of the project usually use #missingmaps in their changeset.
  2. Contributors that utilized the Maps.Me app: The ‘created_by’-tag contains ‘MAPS.ME’.
  3. All other ‘regular’ contributors of the OSM project, who don’t have any #missingmaps in their changesets and neither used the maps.me editor.

In the past 12 months, almost 1.53 million members registered to the OSM project. So far, only 12% (181k) ever created at least one map edit: Almost 12,000 members created at least one changeset with the #missingmaps hashtag. Over 70,000 used the maps.me editor and 99,000 mapped without #missingmaps and the maps.me editor. The following diagram shows the number of new OSM contributors per month for the three aforementioned groups.

2016permonth

The release of the maps.me app (more specifically the OSM editor functionality) clearly has an impact on the monthly number of new mappers. Time for a more detailed analysis about the contributions and mapping times: The majority of the members of the groups don’t show more than two mapping days (What is a mapping day, you ask? Well, my definition would be: A mapping day is day, where a contributor created at least one changeset). Only around 6% of the newly active members are contributing for more than 7 days.

2016mappingdays

Some members of the #missingmaps group also contributed some changesets without the hashtag. But many of those members (70%) only contributed #missingmaps changesets. Furthermore, 95% of this adjusted group doesn’t map for more than two days. Anyway, despite identifying three different contributor groups, the results are looking somewhat similar. Let’s have a look at the number of map changes. The relative comparison shows that the smaller #missingmaps group produces a large number of edits. The maps.me group only generates small numbers of map changes to the project’s database.

2016mapchanges

Lastly, I conducted an analysis for three selected tag-keys: building, highway and name. The comparison shows that the #missingmaps group generates a larger number of building and highway features. In contrast “regular” OSM’ers and maps.me users contributed more primary keys such as the name- or amenity-tag.

2016tags

I think the diagrams in this blog post are quite interesting because they show that the #missingmaps mapathons can activate members that contribute many map objects. But they also indicate that the majority of these elements are traced from satellite imagery without primary attributes. In contrast the maps.me editor functionality proofed to be successful with its in-app integration and its easy usability, which resulted in a huge number of new contributors. In summary, I think it would be good to motivate contributors not only to participate in humanitarian mapathons but also to map their neighborhood in an attempt to stick to the project. Also, I guess it would be great if the maps.me editor would work on the next steps in providing easy mapping functionality for its users (of course with some sort of validation to reduce questionable edits).

Thanks to maɪˈæmɪ Dennis.

Unmapped Places of OpenStreetMap – 2016

Back in 2010 & 2011 I conducted several studies to detect underrepresented regions a.k.a. “unmapped” places in OpenStreetMap (OSM). More than five years later, some people asked if I could rerun the analysis. Based on the latest OSM planet dump file and Taginfo, almost 1 million places have been tagged as villages. Furthermore, around 59 million streets have a residential, unclassified or service highway value. My algorithm to find unmapped places, works as follows:

  1. Use every place node of the OSM dataset which has a village-tag (place=village).
  2. Search in a radius of ca. 700 m for a street with one of the following highway-values: residential, unclassified or service.
  3. If no street can be found, mark the place as “unmapped”!

My results for the entire OSM planet can be found under the following webpage.

unmapped

Overall we have more than 440,000 unmapped places in OSM. As you can see in the picture above, most of the places are around Central Africa, Saudi Arabia or China. However, I hope that this analysis helps to complete some of the missing areas or to revise some incorrect map data. Some remarks about “false=positives” or why your village is marked as unmapped? Some possible reasons: Is the used tag for your place correct? Compare the wiki page for further information. Sometimes “hamlet” could be the correct tag value. Are the nearby highways tagged correctly? (OSM wiki)

Amount of unmapped places for each continent:

  • Africa 119,084
  • Asia 241,833
  • Australia 212
  • Europe 44,819
  • North America 16,464
  • Oceania 837
  • South America 15,576

Technical Stuff: The OSM data for the analysis is prepared by a custom OSM PBF reader. The webpage, which shows the results, is based on Leaflet 1.0.0-rc1 and the really fast PruneCluster plugin.

*Update*: You’ll find the date of the latest data update in the header -> “(Date: Apr. 9th, 2018)”

Thanks to maɪˈæmɪ Dennis.

Verified OpenStreetMap contributor profiles?

The reputation of a contributor in OpenStreetMap (OSM) plays a significant role, especially when considering the quality assessment of the collected data. Sometimes it’s difficult to make a meaningful statement about a contributor by simply looking at the raw mapping work represented by the number of created objects or used tags. Therefore, it would be really helpful if we would have some additional information about the person who contributes to the project. For example: Does she/he help other contributors? Is her/his work somehow documented or based on one of the “discussed” proposals? Or does she/he work as a lone warrior in the OSM world?

In 2010 I created “How did you contribute to OpenStreetMap?” (HDYC) as a kind of fun side project. Nowadays many people use it to get some detailed information about OSM contributors. Some of you are probably familiar with the “verified” icon used on some celebrity Twitter accounts. I created a similar new feature for the aforementioned HDYC page. If you connect your related OSM accounts, your profile will be marked as “verified”.

verified

What do you have to do to get a verified contributor profile, you ask? First of all, you have to create at least 100 OSM changesets. Secondly, you need a login (username) for the OSM Help Forum, for the common OSM Forum and for the OSM Wiki. Last but not least, you have to list your OSM related accounts on your OSM profile page. After that, you should be able to see your accounts in your HDYC profile and your account will be automatically marked as verified.

Malenki already mentioned his usernames as an example in his profile. He also described it in a tiny OSM diary. Overall this feature is optional. So if you don’t want to “connect” or show your accounts for privacy protection, please don’t mention them on your OSM profile. My script checks the OSM profiles of the latest active OSM contributors every 24h. That’s it.

The HDYC profile now also shows the number of your changeset discussions and, if mentioned in your OSM profile, the page shows your Mapillary account as well.

Notice: If someone is trying to cheat with other people’s accounts, I will blacklist her/his username.

Thanks to maɪˈæmɪ Dennis.

Good #Hashtags in OpenStreetMap Changesets

#Hashtags are commonly used on Twitter to find content for a specific topic. Also in the OpenStreetMap (OSM) universe they are popular and utilized to mark changesets, which have been contributed during a special event, such as mapping parties or HOT tasks. However, in most cases, they are added in the changeset comment section. Back in November, 2015, several people discussed the pros and cons about (only) this approach. You can find a general overview of good changeset comments here. The aforementioned wiki page also shows why it is important to write a “concise and adequate“ description of the edit. Anyway, I also support the opinion that we should not generalize this statement and only add hashtags in our changeset comments. I prefer the different approach in which the contributor adds an extra changeset tag for the hashtag(s). For example, the widely used JOSM editor allows optional tags (as you can see here). On the other hand, the iD editor, which is used in many cases by new contributors, doesn’t offer this feature. However, I am sure that with some minor changes this could be fixed. A more or less complete set of recommended or mandatory changeset tags can be found here.

As a first step, I optimized my webpage to find and visualize OSM changesets with a specific comment (blog post). You can now search for any term in any tag value of all OSM changesets. So far the search only considers the changeset comments. This means that you can also search for other values such as the editor that was used or the source (imagery).

For example, you can now create interesting statistics, such as a comparison of editors used in OSM. Have a look at the kind of created objects, amount of map changes or countries …

JOSM/1.5

JOSM/1.5

iD 1.9.2

iD 1.9.2

Thanks to maɪˈæmɪ Dennis.

How to detect suspicious OpenStreetMap Changesets with incorrect edits?

Since its rise in popularity, the well-known online encyclopedia Wikipedia has been struggling with manipulation or, in the worst-case, vandalism attempts. Similarly, the OpenStreetMap (OSM) project suffered several times over the past few years of cases where incorrect map data edits were made. These erroneous edits can stem at times from (new) contributors or illegal data imports (or automated edits) which have not been discussed in advance with the community or the Data Working Group (DWG) and corrupted existing project data. The current OSM wiki page gives a great overview about general guidelines and e.g. types of vandalism. Another page in the wiki also mentions a prototype of a rule based system for the automatic detection of vandalism in OSM, which I developed in 2012. However, the system has never actually been implemented. Today, the contributors of OSM can use a variety of different tools to inspect an area or particular map changes. A few of them are listed below (complete list can be found here):

Based on the database which I use for multiple other services, I created an easy to use webpage to find suspicious OSM changesets with possibly incorrect map edits. The webpage offers some filter options such as the boundary of a country or the object change of interest. In contrast to the other aforementioned webpages you can also filter changesets based on the active “mapping days” of the contributor. A “mapping day” is a day on which the contributor created at least one changeset, independent from the registration date. I am also planning on adding additional user reputation information such as used editors or tagging behavior. And of course I am going to add some RSS feeds in the next version. The first version can be found here.

OSMSuspicious

What makes all of this different from other tools? Well, I think one of the major advantages is the simplicity of the webpage and that you can filter changesets based on the contributor activity and/or the changeset edits. In contrast to other tools, you can find changesets not only based on your area of interest, but also based on potential beginner mistakes and hopefully not vandalism attempts or fictional/ none existing map data.

Find Suspicious OSM Changesets here: http://resultmaps.neis-one.org/osm-suspicious

Thanks to maɪˈæmɪ Dennis.

OpenStreetMap Crowd Report – Season 2015

Almost one year has passed again. This means it’s time for the fourth OpenStreetMap (OSM) member activity analysis. The previous editions are online here: 2014, 2013 and 2012. Simon Poole already posted some interesting stats about the past few years. You can find all his results on the OSM wiki page. However, similar to last year, I try to dig a little deeper in some aspects.

Overall the OSM project has officially more than 2.2 million registered members (Aug, 9th 2015). For several of my OSM related webpages I create a personal OSM contributor database, based on the official OSM API v0.6. Anyway, when using this API, the final table will show a list with more than 3 million individual OSM accounts (Aug, 9th 2015). I’m not sure what the cause for this gap of almost 1 million members between the official number and the member number extracted with the API could be. Maybe some of you have a possible explanation? However, I think many accounts are created by spammers or bots.

The following chart shows a trend similar to the one of previous years: The project attracts a large number of newly registered members, but the sum of contributors that actively work on the project is fairly small. As mentioned in earlier posts, this phenomenon is nothing special for an online community project and has been analyzed for previous years already.

2015OSMMembers

Described in numbers (July 31st, 2015):

  • Registered OSM Members (OSM API): 3,032,954
  • Registered OSM Members (Official): 2,201,519
  • Members who created 1 Changeset: 562,670
  • Members who performed >= 10 Edits: 343,523
  • Members who created >=10 Changesets: 137,591

Personally, I really like the following diagram: It shows the increase in monthly contributor numbers over the past few years and their consistencies in collecting OSM data based on the first and latest contributed changeset of an OSM member. It’s great to see that at least some experienced mappers are still contributing to the project after more than five years.

2015OSMMembersSince

Some background information on how I created the stats: To retrieve the registration date of the members, I used the aforementioned OSM API. The other numbers are based on the OSM changeset dump, which is available for download here.

Next to the presented results above, you can find some daily updated statistics about the OSM project on OSMstats.

Thanks to maɪˈæmɪ Dennis.

Counting changes per Country – A different approach

OSMstats contains several statistics about the OpenStreetMap (OSM) project, such as daily-created objects, the amount of active contributors or detailed numbers for individual countries. One way to determine the sum of created or modified Node objects, is to use the minutely, hourly or daily OSM replication change files and counting the values for each country of the world. Sadly, this approach has some drawbacks. Firstly, the official files do not contain, for example, all Nodes of a modified way, which is required, when trying to find the country where the change took place. Furthermore, the determination of the country for a specific OSM object really depends on the border’s level of detail: More detailed country borders make the processing quite time-consuming. Some of you probably experienced this problem before when using Osmosis or a different OSM processing tool. Anyway, for calculating additional country statistics I tried a new approach:

  1. Determine the country of a changset based on its center position
  2. Use the changeset country information for all objects within this changeset.

map

Of course, the determined country of the changeset can “only” be generalized for the entire changeset content, but how does it compare with the current method utilized in OSMstats? I compared last week’s numbers of OSMstats for each country of the world with the newly introduced approach. In total, the number of active members per country differs for each weekday by around 3% (min. 1% and max. 5%). The average difference of created, modified and deleted Nodes per country is quite similar with 4% (min. 2% and max. 9%). The presented approach could produce partially incorrect results whenever a changeset contains border changes of two or more countries or if the center of the changeset is in the wrong country. But IMHO the assumption to use the changeset centers is sufficient to calculate results and determine changes per country. As you can see in the figure above, most OSM changesets happen in a manageable area within one country. Yes I know, exceptions prove the rule.

So, why am I doing this? The main idea behind this approach is to change the entire processing task for OSMstats within the coming weeks. The changes per country will then be based on the introduced approach. Another advantage will be, that this newly created information, gathered from the changesets, can be utilized to create additional contributor statistics.

Thanks to maɪˈæmɪ Dennis.

Ebola Response Map and OSM contributor analysis

For almost eight months the OpenStreetMap (OSM) community has been collecting geo information for the West Africa Ebola outbreak response now. The collective work of the crowd is somewhat managed by the Humanitarian OpenStreetMap Team (HOT). For example, the Task Manager provided by HOT gives interested contributors information in which areas map features are needed. However, you can find additional information in an article by Pierre Beland, which he wrote during a conference where he presented the efforts of the OSM community. The OSM wiki contains some useful information about the West Africa Ebola Response too. Matt Irwin also wrote a summary about the OSM mapper contributions and created an interesting visualization of all the mapping work.

I created a response map for the OSM mapping activities in West Africa, a similar approach as I previously used for the “Typhoon Haiyan” deployment. It displays all OSM changesets created since March 1st, 2014. The analysis extent is displayed by a black rectangle. In total, more than 2,000 contributors made more than 10 million changes to the map. At the bottom you will find a time range slider which can control the displayed changesets. Sorry for the sometimes slow performance, but the community (maybe you too) collected a huge amount of data! The map is online here: http://resultmaps.neis-one.org/osm-ebola

osm_ebola_page

A complete list of all OSM contributor names with their number of map changes can be found here. It’s really fantastic, “Thank you & keep up the good work!”. This time I have also spent some time to analyze what type of contributors helped in this scenario. The following diagram shows the number of contributors per month in the above mentioned analysis extend. Additionally, it contains information on how long the individual contributors have been collecting map data. In contrast to the first months, many new members contributed data in the past three months.

ContributorActivityMembership

Based on the information from “How did you contribute to OSM“, which shows in what country a member performed the most map changes, I created the following chart. It displays the distribution of the contributor’s countries of origin. I assume that the high number of new registered members, who created many changesets during their Ebola response, moved their origin towards West Africa. However, overall more than 2,000 contributors from almost 110 countries helped so far, AWESOME! What do you think?

ContributorsOrigin

Lastly, I would like to point to the following blog post which shows you how to search for changesets with a specific comment for any region of the world: “Filtering OpenStreetMap Changesets by a Specific Comment“.

Thanks to maɪˈæmɪ Dennis.