Below we talk about 3 parts of the Census data being released: splitting Census blocks; Census improvements to the underlying geography; and relating 2000 Census data to 2010 Census geography.

Underlying Census Geography

Anyone familiar with 2000 TIGER data will remember inner city streets that are straight in real life but were not straight in the TIGER data.  In their 2010 geography files, Census undertook a program called MAF/TIGER Accuracy Improvement Project to get the TIGER data closer to “ground truth.”  This is good news for everyone.  It means GIS data from other data sources will be more easily relatable to Census TIGER data.  And it means we can overlay Census data on top of Google Maps and other services and see maps that are still accurate.

Precinct lines (grey) following Google Maps’ streets very closely in Northern Virginia:

But they aren’t exactly the same.  Here, in Northern New Jersey the grey precinct lines appear to be straight along Google’s curvier street; or cut awkwardly across Google’s parcels:

Splitting Census Blocks

As part of its population tabulation program, the Census redraws Census blocks.  In many cases, they split up 2000 Census blocks into multiple 2010 blocks.  This is the natural thing that happens as population grows into new areas.  Another case is combining 2000 census blocks into a single 2010 block.  There are tens of thousands of cases of each in every state.

Below we see Brambleton, Virginia, where new development over the last decade has split a few big Census 2000 blocks into numerous census 2010 blocks:

In Herndon, Virginia, we find an example of 7 Census 2000 blocks that were merged into 3 Census 2010 blocks:

Relating 2000 Data to 2010 Geography

A close study of all this new data reveals a challenge.  The ACS data is on the 2000 census geography, and can’t be related directly to the 2010 census geographies.  Helpfully, Census has provided 2000 tabulation areas (such as blocks) in the re-aligned 2010 geography.  That makes relating the 2000 and 2010 geography a hard, but solvable, problem.

In an effort to promote transparency in using this census data, we will provide on this site work we do translating between 2000 census geography and 2010 census geography, with some best practices and suggestions along the way.  (The census has promised to do this work at some point as well).

The first file we have done is a translation between 2000 Census Blocks and 2010 Census Blocks in Virginia.  We will post more files here in the near future.

Our translation has to account for both of these cases previously noted: 2000 census blocks split into multiple 2010 census blocks; and the case of 2000 census blocks being combined into one 2010 census block.   That makes this translation file a many-to-many relationship between 2000 census blocks and 2010 census blocks.

Questions and comments should be directed to Mike Conlow:  ConlowM at dnc dot org

Authentication

Using any DNC API requires the use of an API key. By default all API key users are rate limited to 100 requests per hour – if your application requires a higher volume key, please get in touch.

Looking Up a Polling Place

To lookup a polling place, perform a GET on http://services.dnc.org/places/lookup with the following parameters:

Required parameters:

• address: the URL-encoded house number and street name to look up, i.e. “address=2005%20Pimmit%20Dr”
• postal_code: the 5-digit ZIP code that goes along with the address, i.e. “postal_code=22043″
• your API key: i.e., “key=YOUR_API_KEY”

OR

• zip9: the 9 digit ZIP+4 code whose precinct you are trying to find.  Most people do not know their ZIP+4, but lookups with address and postal_code will return the “plus4″ portion of the ZIP+4 (zip9 lookups do not return the plus4). i.e., “zip9=220431408″
• your API key: i.e., “key=YOUR_API_KEY”

Examples

Performing a GET to http://services.dnc.org/places/lookup?address=2005%20Pimmit%20Dr&postal_code=22043&key=YOUR_API_KEY will result in HTTP status code 200 (successful) response with the following body which is a JSON hash object:

{“region”:”VA”,
“precinct_name”:”315 – Pimmit”,
“polling_location”:”PIMMIT HILLS CENTER”,
“location_description”:null,
“address”:”7510 LISLE AVE”,
“locality”:”FALLS CHURCH”,
“postal_code”:”220431050″,
“latitude”:38.916322,
“longitude”:-77.204321,
“precision”:”address”,
“precinct_code”:”0315″,
“polling_location_contact_info”:null,
“van_precinct_id”:295851,
“plus4″:”1408″
}

The returned fields are:

• region: The 2-letter state abbreviation for the state this polling place is in.
• precinct_name: The name of the precinct this polling place resides in.
• polling_location: The name of the polling place.
• location_description: Usually blank, but can have additional information like “Room 2-B” or other descriptive information.
• address: The number and street of the polling place.
• locality: The city of the polling place.
• postal_code: The ZIP+4 code for the polling place.
• latitude: The latitude of the polling place, achieved by geocoding the address.  See precision to know how accurate this is.
• longitude: The longitude of the polling place, achieved by geocoding the address.  See precision to know how accurate this is.
• precision: The granularity achieved during the geocoding of the address.  If the precision is “address” then it is likely that services such as Google Maps will be able to provide driving directions.  If it is “street” or “zip” or anything else, the coordinates will not be meaningful enough to use.
• precinct_code: The code for this polling place assigned by the precinct.
• polling_location_contact_info: The person responsible for the accuracy of this polling place.  Usually blank.
• van_precinct_id: An internal primary key used to identify polling places.  This is the value passed to the /show API endpoint to retrieve details about a polling place without having to lookup an address in that precinct.
• plus4: This is the last 4 digits of the ZIP+4 for the address that was used to look up the polling place.  Note that it is usually different
  from the last 4 digits of “postal_code” as the polling place and the voter do not usually share ZIP+4.  You can use this information to better geocode the voter’s address by appending it to their ZIP code on services such as Google Maps or use it in subsequent calls to lookup that voter.

Error conditions:

If the address you provide is valid but we can’t locate the polling place, you will receive an HTTP status code 200 (successful) response but the JSON object will have an “error” property.  It may also have additional information about where to go to find your polling place to help assist people with finding out their polling location.

{“error”:”No polling place found.”,
“region”:”FL”,
“region_name”:”Florida”,
“website”:”http://election.dos.state.fl.us/”,
“voter_information”:”http://election.dos.state.fl.us/”,
“phone”:”8663086739″}

The response fields are:

• error: The cause of the error response.
• region: The abbreviated state of the query address.
• region_name: The full name of the state from the query address.
• website: The Secretary of State or Board of Elections website for the state.
• voter_information: The Secretary of State or Board of Elections website for the state, may be the same as the website.
• phone: The phone number for the Secretary of State or Board of Elections.

If the address doesn’t seem valid, or we cannot determine the state of the address, the error response body will just contain:

{“error”:”No polling place found.”}

Showing a Polling Place

To retrieve the details for a polling place for which you already have
the van_precinct_id, perform a GET to
http://services.dnc.org/places/show with the following parameters:

- id
The van_precinct_id from a previous polling place lookup.
- key
Your API key.

Examples:

Performing a GET to http://services.dnc.org/places/show?id=295851&key=YOUR_API_KEY will result in a JSON hash object being returned like the following:

{“region”:”VA”,
“precinct_name”:”315 – Pimmit”,
“polling_location”:”PIMMIT HILLS CENTER”,
“location_description”:null,
“address”:”7510 LISLE AVE”,
“locality”:”FALLS CHURCH”,
“postal_code”:”220431050″,
“latitude”:38.916322,
“longitude”:-77.204321,
“precision”:”address”,
“precinct_code”:”0315″,
“polling_location_contact_info”:null,
“van_precinct_id”:295851
}

Error conditions:

In the case of an invalid ID being passed, the API will return a 404 Not Found HTTP response with no body.

JSONP Support

If you want to consume the Polling Place API from a webpage, you can use Javascript and JSONP without the need for any server-side code.  Just append “.jsonp” to the URL and pass the required parameters.

For lookups:

http://services.dnc.org/places/lookup.jsonp?address=2005%20Pimmit%20Dr&postal_code=22043&key=YOUR_API_KEY

http://services.dnc.org/places/lookup.jsonp?zip9=220431408&key=YOUR_API_KEY

For showing a polling location:

http://services.dnc.org/places/show.jsonp?id=295851&key=YOUR_API_KEY

JSONP queries can contain a callback parameter or variable name
parameter (or both):

- callback
the name of a Javascript method to call on the returned JSON response, i.e. “callback=processPollingLocation”
- variable
the name of a Javascript variable that you would like the returned JSON object to be assigned to, i.e. “variable=polling_place”

Examples:

Performing a GET on

http://services.dnc.org/places/lookup.jsonp?address=2005%20Pimmit%20Dr&postal_code=22043&key=YOUR_API_KEY&callback=foo&variable=bar

returns:

var bar = {“region”:”VA”,”precinct_name”:”315 -
Pimmit”,”location_description”:null,”address”:”7510 LISLE
AVE”,”latitude”:38.916322,”precinct_code”:”0315″,”plus4″:”1408″,”postal_code”:”220431050″,”polling_location_contact_info”:null,”locality”:”FALLS
CHURCH”,”precision”:”address”,”longitude”:-77.204321,”van_precinct_id”:295851,”polling_location”:”PIMMIT
HILLS CENTER”}; foo(bar);

This can be evaluated as Javascript client-side and uses the JSONP
method to get around cross-domain connectivity issues.

Help

If you have problems or questions, please send a message to the Open.Dems mailing list

The groundbreaking OFA Canvass app gives you everything you need to canvass-right in the palm of your hand. You’ll have instant access to detailed lists of neighbors, interactive maps, and real-time reporting of how many doors were knocked and how the conversations went. With less than three weeks until the November 2 elections, it’s more important than ever that our supporters have the freedom to knock on doors whenever and wherever they can.

Our new app is the latest example of Organizing for America’s deep commitment to using the latest technology to empower voters and volunteers. After all, the one-on-one conversations that the app enables will have a direct effect on whether people vote in this November’s elections-and on the decisions they make in the voting booth.

So, what are you waiting for? Download the OFA Canvass Android app before your next canvass.

This new feature also motivated us to take a closer look at the costs and benefits of including share links and the “tweet” and “like” buttons on the signup forms on our site. We were concerned that including these links and buttons might result in fewer signups. Extensive usability research has shown that any distraction from the main action on a webpage lowers the chance that users will take that action. But we also thought that having people announce their intention to vote in 2010 to everyone on their social network might pay off big if their friends decide to get involved.

Here’s what we found:

• Adding Twitter “tweet” and Facebook “like” buttons to the Commit to Vote page resulted in a 1.25 percent decrease in conversion rate.
• We found that only 0.3 percent of all commitments to vote came from supporters who clicked through on share links from their friends.

Our test results suggest we shouldn’t hand you a megaphone before you sign on the dotted line. Instead, we should be putting these features on the follow-up page after the action. That said, share links can be key to growing the reach of a movement’s presence on these networks. On the first day we included the “tweet” button on the Commit to Vote signup page, our DNC Twitter account grew 860% more than its average daily growth rate in the preceding week. Since then, broader deployment of social network buttons has helped increase the growth rates of all our Facebook and Twitter accounts.

For us, posting directly onto social networks is an important way to recruit new supporters and drive key actions. Below is a breakdown of how social networks are bringing in new supporters. There is a clear trend here when it comes to who signs up on our site: many more folks come in response to our social network posts, rather than through links shared by friends. The other clear trend is that Facebook is netting us the most new supporters. This is because Twitter has fewer users and possibly because many tweets are not read in a web-browser.

Although having a heavy social media tie-in might not be appropriate for every page, we’re still pretty thrilled about it. The share links help us reach and engage more potential supporters, which makes our posting on social networks more effective. So now that you’ve read this post, how about letting your friends know?

That’s why I’m so excited about the project I just finished working on: today’s update to the Organizing for America iPhone app, which gives volunteers everything they need to go door to door talking with people about what’s important to them.

The app takes the usual unwieldy accouterments of canvassing—the pen and paper, clipboards, and lists of voters—and puts them all on your mobile phone. It lets you connect with real people wherever you are and whenever you want. It gets rid of the time-consuming process of assembling lists of houses and entering data, and makes it easier for people on the ground to focus on the things that matter: the one-on-one conversations with your neighbors. (And it makes for a pretty exciting video, too.)

For me, this is exciting in a way software seldom is: it’s technology that affects the real world, that can change the lives of the people who use it and those around them. This is why I’m a programmer.

Most importantly, I think it could have the ability to bring a little spark back to the lives of those who have become jaded by the current political scene. Too many people have become disenchanted with the idea that politics can change the world for the better. In a time when moving forward can seem too difficult to bother, this old-fashioned activity—talking to neighbors about their hopes and concerns—might help remind us that change and connection can still happen. OFA volunteers are already out there knocking on doors—more than 200,000 just last weekend—and now it’s easier than ever to join in.

My favorite Obama slogan was always “We are the change we have been waiting for.” We all still are. Get out there. Talk to your friends, to your neighbors, to strangers. That change and energy is still all around us, even if it can be sometimes a little hard to see. But you’ll never find it if you don’t look.

If a simple iPhone app can help even one person to realize that, it’s worth all the e-brochures in the world.

Download the OFA iPhone app, get today’s canvassing update, or learn more here.

Key parts of the new site include our recently released open source software, as well as APIs that we’re making available publicly. We hope that this will allow others to build on what we’ve done, and do new things that we haven’t even dreamed of. The starting point is our Raise Your Vote API— which will allow anyone to build voter-registration focused applications.

Open.Dems gives a behind the scenes look at some of our work, sharing our best practices with an eye toward other practitioners. On the Open.Dems blog, you can see which website splash pages were most effective in growing the BarackObama.com email list, and whether including donate buttons in emails actually raises more money.

Open.Dems is a new resource for campaigns and candidates across the country, and part of the DNC’s unprecedented investment in this year’s elections. We’re both providing state-of-the-art resources to campaigns while opening up the work we’re doing so others can build on it and make it even more effective. With Open.Dems, we’re continuing to take innovations from the 2008 campaign—as well as those from this year like the Raise Your Vote site and widget—and building on that progress heading into campaign season.

Until recently, it was standard practice to include a “Donate” button at the bottom of all advocacy emails that Organizing for America sent to people on the email list.  The thinking was that it gave supporters an easy way to support us financially if they were feeling particularly inspired by the work we’d been doing.  However, we found that many of the subscribers on our email list were expressing dissatisfaction that we seemed to be asking for money too often.  So we decided to test what effect the “Donate” button actually had on supporter response.

In early February of this year, OFA Director Mitch Stewart sent an email to the Organizing for America list asking everyone to use OFA’s online tools to write letters to their local newspapers on the urgent need to pass comprehensive health reform.  For this email, we isolated two randomly selected groups of email subscribers, sent a version of the email with a “Donate” button to one, and sent a version of the email without the “Donate” button to the other.

The response reflected what we’d been hearing from our subscribers: Not only did including the “Donate” button increase the number of email recipients who unsubscribed (by 18.7%*), but it decreased the number who wrote letters (by 9.1%*) and did not increase the number of donations made (the number of recipients who donated from the email with the “Donate” button was equal to the number who donated on their own after taking action from the email with no button).  In short, having the button hurt our advocacy work and did nothing to help our fundraising.

It was clear from this test that sending advocacy emails is not when we should be asking for money.

* Statistically significant with 95% confidence

All API requests are rate limited on a per key basis. This means that you will only be able to make a limited number of API requests in a given time period. You can see how many requests a given API key has left in the current time period through your API Key page, or through HTTP headers that are returned with each API request.

Our API Authentication architecture is powered by Lockbox, an open source middleware for shared API authentication created by the DNC.

We hope that by releasing this API people with innovative online voter registration ideas will be able to build them without the effort that would have otherwise been required.

Authentication

Using any DNC API requires the use of an API key. By default all API key users are rate limited – if your application requires a higher volume key, please get in touch.

In addition to signing up for an API key, you must sign up as a Raise Your Vote partner to use the API key with the voter registration API. You must also associate your API key with your Raise Your Vote partnership in the partner dashboard settings. This will allow registrations submitted via API to appear in your partner dashboard, alongside any registrations collected by partner widget.

Registration Fields

Registration fields are the fields that are required to complete a registration form. These fields vary by state and include the following information for each field.

• name The name of the field.
• required A boolean that indicates whether the field is required.
• help_text Help text that can be displayed to the end user.
• label Human readable label for the field
• options For fields that are constrained to a set, the set of possible options
• validations Validations that can be applied to the field. These will also be enforced by the API when registrations are submitted.

These registration fields are returned as a collection of fields that define the fields for that state. They can be retrieved by performing an HTTP GET of the registration fields resource for that state:

https://www.raiseyourvote.com/api/registration/fields/MA.json?lang=en&key=YOUR_API_KEY

There are some states and territories where registering via the API is not permitted. In those cases, the API will return an appropriate error condition. https://www.raiseyourvote.com/api/registration/fields/WY.json?lang=en&key=YOUR_API_KEY

Registrations

Registrations are created by performing an HTTP POST to the https://www.raiseyourvote.com/api/registrations.json resource. The post must include the following elements as URL encoded key/value pairs on the query string.  The post should have an empty body.

Required Fields

• key The API key to use for this registration.
• registration[address_state] The state that the registration is taking place in.
• registration fields for state The registration fields that the fields API indicate are required for a particular state. The key for each field should be registration[name] where name is the field name supplied by the registration fields API.

Possible Fields
The following fields should be included in the registration if the Registration Fields API indicates that the field is required for a particular state, or if it is necessary to complete a name change or change of address form.

• registration[ethnicity]
• registration[temp_id_number]
• registration[name_title]
• registration[name_first]
• registration[name_last]
• registration[name_middle]
• registration[name_suffix]
• registration[address_city_town]
• registration[address_street]
• registration[address_county]
• registration[address_zipcode]
• registration[birthdate]
• registration[change_current_registration]
• registration[email]
• registration[phone_number]
• registration[gender]
• registration[email_optin]
• registration[sms_optin]
• registration[i18n]
• registration[citizen]

If the user has an optional mailing address:

• registration[mailing_address_city_town]
• registration[mailing_address_state]
• registration[mailing_address_street]
• registration[mailing_address_zipcode]

If the user is changing their address:

• registration[previous_address_city_town]
• registration[previous_address_street]
• registration[previous_address_zipcode]
• registration[previous_address_state]

If the user is changing their name:

• registration[previous_name_first]
• registration[previous_name_last]
• registration[previous_name_middle]
• registration[previous_name_suffix]

Additional Optional Fields
The following fields are also allowed for all registrations, but are not required.

• registration[referer] The HTTP Referrer of the end user.
• registration[ip] The IP address of the end user.
• registration[source] A source code that is persisted with the registration. Can be used for analytics purposes.

Successful registration creation requests will return a url for the PDF that corresponds to the registration that was submitted. In addition, the system will add the registration to the partner dashboard associated with the API key, and send an email to the voter with a link to the PDF for their records.

If the registration is unsuccessful a collection of validation errors will be returned to the API consumer. These should be displayed to the user so they have the opportunity to correct the problem.

Client Libraries

An example client library in Ruby is available for the Voter Registration API.  Examples for PHP and cURL are also available.

Usage

Most uses of the API will follow this pattern:

1. A request is made for the registration fields for the state in which the end users it attempting to register to vote
2. The registration fields are rendered by the consuming application, and the user completes them.
3. A completed registration is collected by the consuming application and submitted to the registrations API.
4. The system responds with a URL for a completed registration form, which the end user is redirected to.
5. The registration is available to administrators in the partner dashboard.

Help

If you have problems or questions, please send a message to the Open.Dems mailing list

Get the widget here.

RaiseYourVote.com is another example of how the Democratic Party is using new media and technology to get voters to the polls this year.

Democratic state parties, blogs, and other partners and groups will now be able to easily register voters through their pages, as well as get access to the names and email addresses of those who they register. As part of Vote 2010, the Democratic Party isn’t just investing money, we’re developing new tools for volunteers and activists across the country to help reach voters.