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There are quite a number of tools and platforms on the market right now. In fact, it is often suprising to see new projects and apps being built from scratch, when it is so cheap and easy to do with other tools.
If you are looking to quickly and easily launch a custom crowdsourced mapping project from your browser, try canvis.app.
Canvis is not as powerful as other tools, but it is fully customizable and supports most use-cases. It works for both large-scale, and small scale projects, but currently lacks polygon and polyline editing and photo uploads. It allows data export to CSV and works on all web browsers and screen sizes.
One of the oldest platforms is Ushahidi. Ushahidi is especially focused on 'crowd reporting' via SMS and other channels.
We built the Ushahidi platform as a tool to easily crowdsource
information using multiple channels, including SMS, email, Twitter and
People can submit reports by:
- Going to the web page
- Sending an SMS
- Using the Android app
It was originally intended as a tool for monitoring election related violence and suspicious activities. It has since been used in Haiti and other disasters. You should be able to adapt it to your purposes. Ushahidi only deals with point data though. If you need to deal with lines and polygons, you're out of luck.
Another option would be Localwiki.
It's a tool for collaborating in local, geographic communities. It has integrated support for mapping. Your users can delineate an area or trace a line on the map and then write what they know about it on a wiki page.
Every feature of a local wiki involves a place: where news events
happen, where sites are found, where neighborhood boundaries are, and
how to get from point A to point B.
I think it would be useful to consider what might motivate the masses to participate.
While Greed and Fear are traditionally used to describe stock market behavior, I think it can be generalized to describe crowdsourcing. IMO a stockmarket is really a form of crowdsourcing - the crowd is used to determine the price of a share.
I've worked on crowdsourcing for a 911 emergency notification system. People fear not being notified in the event of a nearby emergency. I've never played it but I think greed might be the underlying motivation for participation in FourSquare.
Here's a good example, of simple crowd sourcing that asks people to volunteer two items of information:
- What is your zip code?
- Is that zipcode in the Midwest?
Other ideas, depending on your project:
- http://wikimapia.org/ defines places in the simplest form (a box) and allows users to add information about the place. It has very widespread adoption (>1 million users) and is used by a non technical audience.
- Wiki's. A lot of information in Wikipedia is linked to a particular geography through category's and special tags. It doesn't need to be a map to be spatial.
- It is also possible via geoparsing to make a body of text spatial. Ask your users to provide information as text and then extract the spatial information.
- Pen and Paper. Give stakeholders a map to print and ask them to mark up with a pen. Ask them to email a scan, or give a postal address.