postal code-->electoral district: a free + legal way

[Jennifer Bell]

It came out on the changecamp discussion group that there may be a free, legal solution for the postal code->electoral district issue using two services:

1. pcode->geocode at geocoder.ca
2. Cory's geocode->EDID lookup API

I tried it for my postal code and it worked.  Could be good!

Original discussion here:

http://groups.google.com/group/changecamp/browse_thread/thread/5e3e9d3a80cd3465

Jennifer
http://visiblegovernment.ca



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[Daniel Haran]

The problem there is that it returns the centroid (central point) for
the postal code. This works for the majority of postal codes areas
that do not overlap electoral districts.

d.

On Wed, Jan 28, 2009 at 11:20 PM, Jennifer Bell <[hidden email]> wrote:

>
> It came out on the changecamp discussion group that there may be a free, legal solution for the postal code->electoral district issue using two services:
>
> 1. pcode->geocode at geocoder.ca
> 2. Cory's geocode->EDID lookup API
>
> I tried it for my postal code and it worked.  Could be good!
>
> Original discussion here:
>
> http://groups.google.com/group/changecamp/browse_thread/thread/5e3e9d3a80cd3465
>
> Jennifer
> http://visiblegovernment.ca
>
>
>
>      __________________________________________________________________
> Yahoo! Canada Toolbar: Search from anywhere on the web, and bookmark your favourite sites. Download it now at
> http://ca.toolbar.yahoo.com.
> _______________________________________________
> CivicAccess-discuss mailing list
> [hidden email]
> http://lists.pwd.ca/mailman/listinfo/civicaccess-discuss
>

[Jennifer Bell]

Isn't that a problem with all postal code to electoral district resolvers?

Jennifer


--- On Thu, 1/29/09, Daniel Haran <[hidden email]> wrote:

> From: Daniel Haran <[hidden email]>
> Subject: Re: [CivicAccess-discuss] postal code-->electoral district: a free +  legal way
> To: [hidden email], "civicaccess discuss" <[hidden email]>
> Received: Thursday, January 29, 2009, 8:27 AM
> The problem there is that it returns the centroid (central
> point) for
> the postal code. This works for the majority of postal
> codes areas
> that do not overlap electoral districts.
>
> d.
>
> On Wed, Jan 28, 2009 at 11:20 PM, Jennifer Bell
> <[hidden email]> wrote:
> >
> > It came out on the changecamp discussion group that
> there may be a free, legal solution for the postal
> code->electoral district issue using two services:
> >
> > 1. pcode->geocode at geocoder.ca
> > 2. Cory's geocode->EDID lookup API
> >
> > I tried it for my postal code and it worked.  Could be
> good!
> >
> > Original discussion here:
> >
> >
> http://groups.google.com/group/changecamp/browse_thread/thread/5e3e9d3a80cd3465
> >
> > Jennifer
> > http://visiblegovernment.ca
> >
> >
> >
> >    
> __________________________________________________________________
> > Yahoo! Canada Toolbar: Search from anywhere on the
> web, and bookmark your favourite sites. Download it now at
> > http://ca.toolbar.yahoo.com.
> > _______________________________________________
> > CivicAccess-discuss mailing list
> > [hidden email]
> >
> http://lists.pwd.ca/mailman/listinfo/civicaccess-discuss
> >

      __________________________________________________________________
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[Daniel Haran]

On Thu, Jan 29, 2009 at 9:06 AM, Jennifer Bell <[hidden email]> wrote:
>
> Isn't that a problem with all postal code to electoral district resolvers?
>
> Jennifer

Well, something is definitely fubared with these lists, because they
don't all return the same results.

Technically though, it should be an area overlap. For those postal
codes that overlap 2 or more EDIDs, all possibilities should be
returned in a query.

Otherwise, we mislead a fraction of voters.

d.

> --- On Thu, 1/29/09, Daniel Haran <[hidden email]> wrote:
>
>> From: Daniel Haran <[hidden email]>
>> Subject: Re: [CivicAccess-discuss] postal code-->electoral district: a free +  legal way
>> To: [hidden email], "civicaccess discuss" <[hidden email]>
>> Received: Thursday, January 29, 2009, 8:27 AM
>> The problem there is that it returns the centroid (central
>> point) for
>> the postal code. This works for the majority of postal
>> codes areas
>> that do not overlap electoral districts.
>>
>> d.
>>
>> On Wed, Jan 28, 2009 at 11:20 PM, Jennifer Bell
>> <[hidden email]> wrote:
>> >
>> > It came out on the changecamp discussion group that
>> there may be a free, legal solution for the postal
>> code->electoral district issue using two services:
>> >
>> > 1. pcode->geocode at geocoder.ca
>> > 2. Cory's geocode->EDID lookup API
>> >
>> > I tried it for my postal code and it worked.  Could be
>> good!
>> >
>> > Original discussion here:
>> >
>> >
>> http://groups.google.com/group/changecamp/browse_thread/thread/5e3e9d3a80cd3465
>> >
>> > Jennifer
>> > http://visiblegovernment.ca
>> >

[Glen Newton]

> Otherwise, we mislead a fraction of voters.

Careful: you might be accused of being politicians!  ;-)

-glen

2009/1/29 Daniel Haran <[hidden email]>:

> On Thu, Jan 29, 2009 at 9:06 AM, Jennifer Bell <[hidden email]> wrote:
>>
>> Isn't that a problem with all postal code to electoral district resolvers?
>>
>> Jennifer
>
> Well, something is definitely fubared with these lists, because they
> don't all return the same results.
>
> Technically though, it should be an area overlap. For those postal
> codes that overlap 2 or more EDIDs, all possibilities should be
> returned in a query.
>
> Otherwise, we mislead a fraction of voters.
>
> d.
>
>
>> --- On Thu, 1/29/09, Daniel Haran <[hidden email]> wrote:
>>
>>> From: Daniel Haran <[hidden email]>
>>> Subject: Re: [CivicAccess-discuss] postal code-->electoral district: a free +  legal way
>>> To: [hidden email], "civicaccess discuss" <[hidden email]>
>>> Received: Thursday, January 29, 2009, 8:27 AM
>>> The problem there is that it returns the centroid (central
>>> point) for
>>> the postal code. This works for the majority of postal
>>> codes areas
>>> that do not overlap electoral districts.
>>>
>>> d.
>>>
>>> On Wed, Jan 28, 2009 at 11:20 PM, Jennifer Bell
>>> <[hidden email]> wrote:
>>> >
>>> > It came out on the changecamp discussion group that
>>> there may be a free, legal solution for the postal
>>> code->electoral district issue using two services:
>>> >
>>> > 1. pcode->geocode at geocoder.ca
>>> > 2. Cory's geocode->EDID lookup API
>>> >
>>> > I tried it for my postal code and it worked.  Could be
>>> good!
>>> >
>>> > Original discussion here:
>>> >
>>> >
>>> http://groups.google.com/group/changecamp/browse_thread/thread/5e3e9d3a80cd3465
>>> >
>>> > Jennifer
>>> > http://visiblegovernment.ca
>>> >
> _______________________________________________
> CivicAccess-discuss mailing list
> [hidden email]
> http://lists.pwd.ca/mailman/listinfo/civicaccess-discuss
>

--

-

[Daniel Haran]

On Thu, Jan 29, 2009 at 9:30 AM, Glen Newton <[hidden email]> wrote:
>> Otherwise, we mislead a fraction of voters.
>
> Careful: you might be accused of being politicians!  ;-)
>
> -glen
>

They only try to mislead a fraction? :O

d.

[Joe Murray]

The Elections Canada / StatsCan list for PC -> EDID is known to have
significant data quality issues unrelated to a postal code geographically
overlapping riding boundaries. There are up to 7 ridings for a single postal
code in their data last I looked, with tens of thousands of postal codes
having multiple entries if I recall correctly. The methodology they've used
to create the table is the issue.

> <[hidden email]> wrote:
> >
> > Isn't that a problem with all postal code to electoral district
> resolvers?
> >
> > Jennifer
>
> Well, something is definitely fubared with these lists, because they
> don't all return the same results.
>
> Technically though, it should be an area overlap. For those postal
> codes that overlap 2 or more EDIDs, all possibilities should be
> returned in a query.
>
> Otherwise, we mislead a fraction of voters.
>
> d.

[Tracey P. Lauriault]

Been away for a couple of days!

These folks did some interesting work here with postal codes but I do not know the level of accuracy - http://www.voteforenvironment.ca/

Jennifer, if you go through the archives of the civicaccess.ca list you will find two or three threads that discuss this file and its accuracy & access issues.

Russel over at Copyright Canada has developed a tool here - http://www.digital-copyright.ca/edid/postal, and has an MP letter writing tool created to request for access to this file that might be helpful for the discussion thread you forwarded earlier.Letter re-postal code file and the tool he used to help you generate it are here - http://www.digital-copyright.ca/edid/letter5.

I also know that Mike over at Open Concept (http://openconcept.ca/services) has done some work with the postal code file and perhaps he can point us to some of the issues he encountered.

Daniel is correct, the issue here is accuracy, you want to make sure that you continuously have the updated file and that you are working with polygon to polygon to ensure you have the correct postal code in the correct riding.  The other tools are not accompanied with metadata and therefore it is uncertain if they did a quality check or what base data they used.  This is a typical problem with may great hacks, no metadata for the user to evaluate the tool, assess the algorithm nor trace the data source.

Cheers
Tracey

On Thu, Jan 29, 2009 at 12:02 PM, Joe Murray <[hidden email]> wrote:

The Elections Canada / StatsCan list for PC -> EDID is known to have
significant data quality issues unrelated to a postal code geographically
overlapping riding boundaries. There are up to 7 ridings for a single postal
code in their data last I looked, with tens of thousands of postal codes
having multiple entries if I recall correctly. The methodology they've used
to create the table is the issue.

> <[hidden email]> wrote:
> >
> > Isn't that a problem with all postal code to electoral district
> resolvers?
> >
> > Jennifer
>
> Well, something is definitely fubared with these lists, because they
> don't all return the same results.
>
> Technically though, it should be an area overlap. For those postal
> codes that overlap 2 or more EDIDs, all possibilities should be
> returned in a query.
>

> Otherwise, we mislead a fraction of voters.
>

> d.

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--
Tracey P. Lauriault
613-234-2805
https://gcrc.carleton.ca/confluence/display/GCRCWEB/Lauriault