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  • Noelle Dwyer, Kate O'Byrne, Natalie O'Dell, Benjamin Heidloff, and Amy Mackinnon

Meet the YouthMappers Validation Hub Members!

Updated: Jan 20, 2022

The YouthMappers Validation Hub is formed of experienced student mappers whose goal is to ensure a high standard of data quality on OpenStreetMap (OSM). Established in May 2019, faculty and students at The George Washington University in Washington, D.C. facilitate and run the Validation Hub. They validate the OSM contributions for YouthMappers' network projects to guarantee the highest quality data. Aligning with the perspective- "we don’t plan on building just maps or mappers, we also build validators," they also provide feedback to OSM users to improve the technique, habits, and conduct of mappers. Read more about the members of the Validation Hub and their experiences below. Learn more about the YouthMappers Validation Hub and their process at

Screenshots from YouthMappers Validation Hub Event in February 2021

Why is validation important for OpenStreetMap?

Amy MacKinnon: Validation helps to verify the quality of OSM data. Because OSM is an open-source platform and technically anyone can add or edit data, it is important that we have more experienced mappers look over edits to ensure that it follows OSM guidelines and reflects the instructions of the task. First, we make sure that everything in the task, including buildings, roads, and waterways, is mapped. Next, we look over the data and make small corrections if need be. Common fixes are things like squaring buildings, correcting tags on roads and buildings, fixing overlapping features, and adjusting roads or buildings to better align with imagery. By going through this process, we make sure that the data we input into OSM is high quality and that it will be ready for the next steps in the mapping process, whether the data is used right away or someone on the ground adds tags based on their local knowledge.

Noelle Dwyer: Validation is the process of reviewing the mapping of OSM users on a task and checking it for completion, tagging accuracy, spatial accuracy, and adherence to project guidelines--we also encourage mappers to return and keep improving their edits. It is a very important process, as it is the last stop before a task or project can be marked as completed and used for humanitarian efforts. Given that many of the projects we work to validate are high-priority--the validation is urgent and time-sensitive--it is essential to have an organized group of people ready to get the work done.

Kate O’Byrne: Validation is a very important step in OSM mapping. After a task has been mapped by volunteer mappers, validators (such as ourselves at the Hub) go in and check to make sure that the map data is aligned with imagery to maintain the quality of OSM data. Some important things to look out for are that buildings are squared off, roads are aligned with the imagery, nodes aren’t overlapping one another, etc. Anyone can contribute to mapping tasks. Having validators helps to make sure that the projects come together to produce high-quality data.

Benjamin Heidloff: Validation is important because it allows people with different perspectives to look at the same task, which makes the buildings, roads, and other points of interest being mapped more accurate. With validation, we make sure that at least two different people will be checking each task (a mapper and a validator), whether the task is an empty field or a dense urban area. Having a solid foundation of the locations of buildings, roads, and other points of interest makes the job easier for individuals on the ground in the local communities being mapped, who then specify community-specific information about local features in the base data. More perspectives means more thorough mapping, which means more accurate features!

What should a YouthMappers member do if they are interested in learning how to validate?

Natalie O’Dell: I would say to first make sure that you are really comfortable with mapping in the basic iD editor platform, make sure you know what to look for when mapping and start trying to notice what other mappers are doing when you are working on tasks. Then it's time to learn how to use Java OpenStreetMap (JOSM) and get really comfortable with mapping and utilizing that platform. JOSM is a really powerful tool for mappers and validators of any level, so being really able to harness the different functions and plugins of JOSM just for mapping tasks sets you up for success when you do move on finally validating. Then of course I would definitely recommend that you take a look at all the guides and information available online, there are so many resources that provide helpful tips and tricks for using JOSM and validating. Being able to reference these resources is so helpful when you do start validating.

Noelle: To someone who is interested in learning how to validate, I would say to take some time to learn to use various other mapping tools along with iD Editor. In addition, it would be very beneficial to you to work on tasks in the HOT (Humanitarian OpenStreetMap Team) Tasking Manager to increase your experience level and range of edits--buildings, roads, agricultural areas, waterways, etc. Before learning how to validate, I worked independently to familiarize myself with Mapillary, MapRoulette, HOT Tasking Manager, and JOSM. This made the process of learning how to validate relatively easy since I was already set up with the primary validation tools. Another thing that’s good to know is that JOSM has a steeper learning curve than iD Editor. It takes time to get used to and learn all the tools and shortcuts that make JOSM so useful, but once you know them it is easy to keep building and improving your skills. Lastly, if you’re interested in validating the best thing to do is to just start researching and learning more about validation.

Amy: One thing that’s really important is learning JOSM, which is the software we use to validate. It allows you to edit many features at once and even has a built-in validation tool that highlights common mistakes. Additionally, it has many helpful plugins that make the process go faster, like a tool to draw buildings and paint styles to highlight overlapping nodes. JOSM is free to download, and there are many resources online for basic, intermediate, and advanced tutorials. YouthMappers also has resources for learning JOSM, as well as documentation for our validation workflow. It can help to familiarize yourself with these things, but it is also important to be an active mapper at your local chapter. Being a frequent contributor to OSM will help you prepare to validate other mapper’s edits and can help you become more involved with the OSM community as a whole.

What do you enjoy most about being a member of YouthMappers Validation Hub?

Noelle: I remember the first mapathon I attended and how excited I was about OpenStreetMap and mapping software in general. As a validator, I am able to connect with so many other mappers having a similar experience to what I had when I was first getting started with mapping. I am able to ensure they get positive and encouraging feedback as well, so they feel welcomed into the community and are more likely to dive deeper into the wide-range of tools OSM has to offer/can be paired with.

Kate: One of my favorite things about being a Hub member is the community I get to be a part of. From my co-members to the people we get to meet through projects and training events, it is a great community to build relationships as we are all working towards a common goal. One of my favorite experiences was getting to help lead a mapping event. At this event, we got to teach people from across the globe about JOSM (Java OpenStreetMap), a free desktop editing tool, and participate in a mapathon where we actively worked to map a Power Mapping project in Nigeria. It was an awesome experience, getting to connect with other people in different time zones and help teach about OSM.

Amy: Being a member of the Hub allows you to get involved with YouthMappers and meet many new people in the broader OSM community. Recently, the Hub ran a validation training event and Mapathon where mappers joined from around the world. It was great to see so many people interested in the Hub and the validation process. We also worked with a chapter in Panama to validate one of their projects. It has been really cool to represent YouthMappers, run our own events, and interact with different chapters and people from all over the world. In terms of the actual validation, it is a nice job because the hours are very flexible and it fits easily into a student’s schedule. The mapping can even be relaxing, and I usually play music or tune into a podcast while I’m working.

Watch the event recording from the session Kate and Amy mentioned here:

What is the favorite task you have validated and why?

Kate: My favorite task that I have validated was for a YouthMappers chapter in Sierra Leone. The Sierra Leone Power Mapping project worked to bring electricity to rural villages and towns struggling with access to adequate electricity to meet their needs. These projects remind me of what is so amazing about the OSM community. There is something so incredible about people from all across the world mapping to create data that can then be used to, for example, get power to villages and towns that need it. Having the opportunity to help contribute data that can then be used to help other parts of the world is why I love working at the Hub.

Why did you join the YouthMappers Validation Hub?

Natalie: I joined the hub because I was really interested in getting involved more with YouthMappers and expanding my knowledge of different aspects of OSM. When I started with the hub I was a fairly advanced mapper in terms of iD editor and had dabbled a little with JOSM, but I had never been involved in the validation process. I wanted to learn more about this process and be involved in a way that was closer to the end of the final product that comes out of the data that is mapped and collected through OSM since that’s really what validating is about. It's the next step in the process after areas are mapped and helps to ensure that the data that is being created is of a high quality.

Benjamin: During my sophomore year, I went to a mapathon at GW (The George Washington University) that featured guest speakers from the World Bank, who spoke about the importance of Humanitarian OpenStreetMap data for the Afghanistan Rural Access Project. I had contributed to OSM before as part of a GIS course the semester before, but I didn’t fully grasp just how directly impactful the contributions to Humanitarian OSM were until talking with the people using it directly in major development efforts. When I saw the opportunity to join the YouthMappers Validation Hub later in my academic career, I knew I had to join!

What skills have you developed from your experience validating?

Natalie: I think being a validator has also really helped to improve the quality of data I put out myself when I’m mapping and has made me a lot more detail-oriented. Even when I’m not necessarily validating areas and I’m just mapping, I tend to think about what I’m doing from the perspective of a validator and definitely pay a lot more attention to the little details in the tasks I’m working on. This is especially true when I am mapping areas that already have some features mapped; I definitely pay a lot more attention now to what other users have already done and how that’s going to inform and impact how I am going to go about working on a task. It has also made me so much more self aware of the impact of the data I am creating in all steps of the process, and that has been very valuable and rewarding to consider.

About the YouthMappers Validation Hub Members!

Noelle Dwyer

Major: Engineering Applied Science with a minor in GIS

University level: Junior

Joined the Validation Hub: October 2020

Hobby/interest outside of mapping: Outside of the Hub, Noelle is a member of the GWU Women’s Volleyball team, is an avid painter, and loves road bicycling.

Kate O’Byrne

Major: Environmental Studies with minors in Sustainability and GIS

University level: Senior

Joined the Validation Hub: June 2020

Hobby/interest outside of mapping: One interesting fact about

Kate is that she was part of two national champion crew teams,

serving as the coxswain in both male and female championship races. A coxswain is a person in charge of steering the boat and managing the rowers.

Natalie O’Dell

Major: International Affairs and Geography with a concentration in Global Public Health and a minor in GIS

University level: Senior

Joined the Validation Hub: June 2020

Hobby/interest outside of mapping: Outside of the Hub, Natalie loves making coffee and enjoys finding new music, she also has her own show as a part of the school’s radio station, WRGW. She currently is a Teaching Assistant for the USAID + YouthMappers Internship program and was previously a GIS

Intern at Central Park. She loves exploring different parks in

cities around the world.

Benjamin Heidloff

Major: International Affairs with a concentration in Security Policy and a minor in GIS

University level: Senior

Joined the Validation Hub: September 2020

Hobby/interest outside of mapping: Outside of YouthMappers, Ben is a GW tour guide and plays the saxophone with the band.

Amy MacKinnon

Major: International Affairs and Geography with minors in GIS and German

University level: Senior

Joined the Validation Hub: September 2020

Hobby/interest outside of mapping: Outside of the Hub, Amy is a GIS intern at a consulting firm and enjoys skiing, hiking, traveling, and cooking in her spare time.


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