Live Validation

Posted by Becky Candy on 9 March 2022 in English.

Live Validation:

Live Validation involves real time data cleaning conducted during a mapathon. It aims to give feedback to mappers as soon as possible after they mark a task in the Tasking Manager as mapped.

How Live Validation is done:

1.A validator joins a mapathon (either remote or in-person) accompanying the mapathon trainer. Ideally the validator gets a chance to introduce themselves near the start of the session and explain their role.

2.Once mapping has started, the validator uses Tasking Manager to focus on most recently mapped tasks: Within a project in the Tasking Manager under the ‘Tasks’ section select tasks that are ready for validation and sort by ‘most recent’. Carry out validation using JOSM and give feedback in the Tasking Manager.

3.After main training elements are covered - validator gives verbal feedback while screen sharing during the mapathon. It tends to be more polite not to mention mapper names - participants typically recognize the task they have been working on when you share your screen.


1.Capture data quality issues very early to prevent further occurrences by giving mapper feedback to improve.

2.Live validation helps the trainer to identify recurring issues where the mappers might need more guidance during the mapathon. The trainer can then adapt quickly and focus their training on those issues.

3.Live validation gives the validator the chance to give verbal feedback while also sharing those issues visually on their screen - this is an impactful way to give feedback, particularly compared to the typical method which only involves text-based feedback.

4.A validator gets the chance to demonstrate feedback channels (Tasking Manager notifications) with mappers to make them aware of where they can find feedback after a mapathon - this improves communication between the mappers and validators.

5.It visually demonstrates what validation is - it can sometimes be a difficult concept for new mappers to gain an understanding of. It gives mappers confidence that their mapping is being checked and this can encourage them to continue mapping.

6.When things go very wrong it demonstrates how much work is needed by a validator to clean things up. This may encourage a greater focus on accuracy by participants. Thereby it may improve data quality and make validation easier and faster.

Task selection


Comment from Puxan on 25 March 2022 at 18:25

In an attempt to achieve the same goals, what I do is review, after the mapathon, the changesets since many times the tiles are not finalized. I try to review the mapping within the week following the mapathon



Comment from jwalseth on 25 March 2022 at 20:38

I think live validation is a great idea. I actually did this the day before you posted this in Slack (joined a mapping event with ~25 people as “embedded validator”). It was very informative. It’s important to sound very friendly, don’t want to intimidate people.

Comment from Becky Candy on 29 March 2022 at 09:44

@Puxan and @Jwalseth Yess you are very right is good to review edits as soon as possible to give feedback and to be very keen not to intimidate mappers, Thank you for the awesome comments

Comment from Chisom on 19 April 2022 at 18:46

This is great and should be encouraged amongst Project/Mapathon Managers.

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