#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

iD 1.9.2

Thanks to maɪˈæmɪ Dennis.

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):

• WhoDidIt
• ITO world OSM Mapper
• Last Week on OSM
• achavi – Augmented OSM Change Viewer

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.

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.

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.

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.

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.

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.

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.

The first book about the OpenStreetMap (OSM) project was written by Frederik Ramm and Jochen Topf, two well-known OSM enthusiasts, in 2008. The first version was in German which was later translated into an improved English version. It contains similar information as can be found in the book by Jonathan Bennett, which was published in 2010, detailing how the projects’ geodata is collected, which editors can be used, some explanations about tags, key and values and how the rendering stack works. Both books are great resources to learn about the OSM basics and to get an overview about useful software.

However, besides these more technical books, the research community has been very active in recent years and has published several articles about OSM data quality, conflation attempts with other datasets or about the contributors of the project. Each of us (Dennis Zielstra and I) wrote a dissertation with different aspects about crowd-sourced geodata and the OSM project: Dennis’ work is about OSM data quality in comparison to proprietary and governmental data with emphasis on pedestrian shortest path routing and data imports. Pascal’s work tackled the issue of how user-generated geodata can be utilized for disabled people friendly route planning. Both dissertations contain more than 13 publications in total.

Now the important part for you: Both dissertations are now freely available. You can download Dennis’ work here and Pascal’s thesis here: Combined more than “480” pages about the OpenStreetMap project!

What can you expect from our dissertations? Our work had to be more science oriented (after all they had to fulfill the strict guidelines our universities gave us to get the PhD). This means it contains a bunch of information that can be useful to other researchers; for example, methods to analyze geodata quality or an introduction on parameters that are important for disabled people in a road network. However, we always tried to make the results and findings always as understandable to the general public as possible. We always felt that VGI research about an open source project such as OSM should not only generate results that are so convoluted that only a hand-full of researchers worldwide would understand the concepts in the end. Any OSM contributor should have a benefit from the findings that are published in those dissertations and we hope we accomplished this goal. We also wished we could have published each publication in open source journals to make the results freely available to everyone but this is a whole new topic for a different blog post. Anyway, by providing the dissertations for free we basically accomplished this task now too.

And what can you not you expect from our work? We do not describe how your object of interest should be tagged or how you should run a mapping event. We feel there are already enough sources out there that tackle these issues.

Anyway, we bet that you will find some information in the dissertations about the OSM project which you have not heard about yet, such as the evolution of the German or the United States OSM street network, analyses about data imports or several research projects about contributor behavior, vandalism detection and a quite comprehensive overview about recent developments and future trends in VGI research in general.

Let us know what you think and enjoy the information overload 🙂

Dennis & Pascal (@pascal_n)

The Missing Maps project is a collaboration between the Humanitarian OpenStreetMap Team (HOT) and various partner agencies, such as the American or the British Red Cross. One of their main objectives is “to map the most vulnerable places in the developing world, in order that international and local NGOs and individuals can use the maps and data to better respond to crises affecting the areas.” You can find additional information about the Missing Maps Project on the OpenStreetMap (OSM) wiki and their project page.

A year ago, I created a webpage where you can filter OSM changesets by a specific comment. Sadly the webpage provides only a search for the latest seven days. However, the Missing Maps project asked me, if it’s possible to “look over a longer time scale”? Here we go, based on a similar concept that I used for a webpage that I created for the HOT Ebola Response, I made a Map that displays all OSM changesets which have the hashtag #MissingMaps in the comment attribute and have been created since August 1st, 2014. It’s online here and being updated on an hourly basis: http://resultmaps.neis-one.org/osm-missingmaps

The webpage also contains overall information about the number of OSM Contributors and map changes. So far more than 800 contributors created more than 1.5 Mio map changes in almost 22,000 changesets. The volunteers contributed in more than 30 countries such as Congo-Kinshasa, Sudan, Central African Republic, Indonesia, Ethiopia, Chad, Zimbabwe or Rwanda. Additionally the number of created changesets and contributors of the last seven days are displayed in two charts at the left-hand side. The time slider at the bottom of the map can be used to show the changesets between two specific dates. Finally an overview page lists the names of all OSM contributors who used the hashtag #MissingMaps in their changesets comment. Same as last time: Thank you & keep up the good work!

Thanks to maɪˈæmɪ Dennis.

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

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.

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?

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.

Gregory Marler had the great idea to implement an “explored” map, based on a concept that some of you might know as “fog of war” from strategy video games. So here you go: I extended my OSM Heat Map with the “Explored Map Style”. It essentially reveals the contribution areas of an OpenStreetMap member in a “fog of war” style. The following figure shows Gregory’s amazing “explored” OSM map.

The Heat & Explored Maps are available for almost all OSM members who contributed at least several changesets here: http://yosmhm.neis-one.org (The new “Explored Map Style” can be selected in the layer panel (upper right corner). Additionally, I added the awesome looking and well known Watercolor and Toner map styles from Stamen design)

Thanks to maɪˈæmɪ Dennis

Maybe some of you are already familiar with “OSMstats”, a website that provides numerous statistics about the OpenStreetMap (OSM) project. The site was created and is maintained by the two guys at altogetherlost.com. However, OSMstats has now been moved to the ResultMaps domain at osmstats.neis-one.org. I added several new features too. First of all, you can now select a specific date for your stats. Secondly, the main menu panel has been extended with a new entry for statistical information about OSM changesets.

Additionally, the graphs for the country statistics, the active members and daily edits are also available in a “year”-overview. I hope you like the new extensions. A big thanks to both guys at altogetherlost.com who originally created OSMstats!

OSMstats is now available at: http://osmstats.neis-one.org
Feel free to check out my Resultmaps too which offer many helpful and funny OSM tools: http://resultmaps.neis-one.org

Notice: OSMstats was introduced in 2011, this means the webpage cannot provide statistics prior to that year. Also, the newly created Changeset-Tab has only data for July, 2014 and after.

Thanks to maɪˈæmɪ Dennis

The OpenStreetMap (OSM) project celebrated its 10th anniversary in August 2014. For almost 10 years it has increased its number of registered members. Even though some contributors stopped their contributions to the project, each day new mappers start collecting features for the free wiki world map (aka database).

In my last contributor report in 2013, the OSM project had a total of 1.3 Mio registered members. For July 2014 this number has increased to almost 1.6 Mio registered members. Similarly to last year, I checked how many contributors created one or more than ten changesets or performed more than 10 map edits. This information can be retrieved from the changeset dump.

The figure above reveals a similar trend to the ones we saw in the past few years: Less than 1/3 of the 1.6 Mio registered members actively contribute to the project (450,000 members). Furthermore, only a small group of 16% (270,000) or respectively 6% (100,000) of the contributors performed more than 10 edits or 10 changesets.

The long-term motivation of the contributors is quite important too. Therefore, similarly to the methods that we presented in our open access publication, I created a figure, which visualizes the increase in monthly volunteer numbers over the past few years and the consistencies in data contributions.

As we already revealed in our study, only half of the monthly active members in OSM are also long-term contributors. Also, the previously discussed pattern which depicts a contributor loss of almost 70% over the years is again visible. However, it is good to see that at least some “senior” mappers still keep contributing to the OSM project.

Thanks to maɪˈæmɪ Dennis