Re: Large Ballot Redux

From: Arthur Keller <arthur_at_kellers_dot_org>
Date: Thu Jun 03 2004 - 11:41:04 CDT

At 12:03 PM -0400 6/3/04, David Mertz wrote:
>On Jun 3, 2004, at 11:18 AM, Alan Dechert wrote:
>>I guess we didn't get a direct answer from David on that, but I'm pretty
>>sure it would be no sweat even for 1-D barcodes. Most of the 76 races would
>>take only one bit each; a few would take 2 or 3 bits. My guess is ~100
>>bits.
>
>If the contests are judicial confirmation or initiatives, there are
>actually three possible votes: Yes; No; No Preference. If we break
>contests at bit boundaries (which as has been discussed, is not
>strictly required, but makes debugging and remediation a LOT
>easier), that's two bits for each such contest.

Only 50 of the races were Yes, No, No preference. So that's 100 bits alone.

>If the contests are between two candidates, that usually amounts to
>four possible votes: Smith (listed); Jones (listed); Write-In; No
>Preference. Fortunately, that still fits in two bits, maintaining
>bit boundaries. This assumes that write-ins are just flagged as
>such in the barcode, the name written in is not directly encoded (it
>requires visual inspection of those ballots).
>
>So an election that was 76 apparently Yes/No contests, would
>actually require 152 bits, using bit-boundaries, i.e. 76*2. Even if
>we didn't respect bit boundaries, we'd need 121 bits, i.e.
>Log2(3^76).
>
>I didn't do the work of going through the actual 76 races (that why
>I made the tool PUBLIC after all :-( ... and then even created a
>friendly web interface to it!). But a few of them had more than two
>candidates, so throw in a few more bits there, maybe 160-170 bits
>using bit-boundaries. And even ignoring bit boundaries, many of the
>contests are 4-option, not 3-option (e.g. Smith vs. Jones, not Judge
>Brown Yes/No), which adds some bits to the absolute optimal
>encoding. So maybe that's 140 bits rather than 121.

Assuming there are between 7 and 14 or so candidates per the other 16
races, that's 4 bits each, or 64 bits.

So that's 164 bits (on bit boundaries) just for the contests alone.
I don't remember how long the prefix for our bar code is. Also, I
don't know how many bits per inch are encoded in the 1-D bar code
we're using.

Best regards,
Arthur

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Received on Wed Jun 30 23:17:04 2004

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