From: Kathy Dopp <kathy_dot_dopp_at_gmail_dot_com>

Date: Fri Jul 21 2006 - 23:18:49 CDT

Date: Fri Jul 21 2006 - 23:18:49 CDT

On 7/21/06,

*> Message: 3
*

*> Date: Fri, 21 Jul 2006 11:30:35 -0700 (PDT)
*

*> From: "Edmund R. Kennedy" <ekennedyx@yahoo.com>
*

*> Subject: Re: [OVC-discuss] approximate solutions
*

*>
*

*> Hello Jerry:
*

*>
*

*> Actually the graphs and tables are still quite useful
*

*> for checking and cutting down orders of magnitude
*

*> errors.
*

*> While it's great to get precise solutions with
*

*> today's calculators and computers, it's much easier to
*

*> display how things relate to the variables with a
*

*> graphical approximation.
*

Ed and Jerry,

I love graphs, but there are four independent variables (election

margin, total #vote counts, desired probability, and the assumed

maximum rate of margin-shifting per machine) and one dependent

variable - the vote count audit sample size. We could make graphs by

holding three of the independent variables fixed and vary one of the

independent variables for each graph, but you would end up with LOTS

of graphs. The three variables with the fewest real life values for

them that would be needed, would be assumed maximum margin

shift/machine, probability and candidate margin, so taking candidate

margins from 1% to say 15% and probabilities of say 90% to 98%, there

could be 15*8 =120 charts that election officials could use to look up

how many vote counts to select for audit if they have N vote counts in

their county - assuming we give them only one option for max vote

counts.

I think that you are suggesting that we could simply do something

like have 15 charts for the 15 margins of interest (assuming that all

races in a county are audited with the same sample size determined by

the race with the smallest margin -- I don't know enough yet to

conclude that would be the case with optical scan ballots that you

could sort to count, but I would assume that would have to be the best

approach with stupid DRE paper rolls) each with nine curves on them

for the nine probabilities they may want.

To do a family of curves for a family of charts to make it easy to

look up values for vote count auditing would require some

decision-making re. the range of values to use to create charts and

curves for.

I agree with you that presenting a book of charts and/or tables for

people to use to calculate vote count audit margins is a good idea

providing the "family of curves" for each desired probability or

candidate vote count margin don't overlap each other illegibly because

then say 120 charts would be needed rather than 15 - but regardless,

this is a big project that a computer would need to generate.

So we still need a program or spreadsheet that will generate the

charts for us, whether from an exact formula if we obtain one, or from

an algorithm.

A book of tables and charts may be more likely to be used than a

spreadsheet that required trial and error or even a computer program

that let users input the four independent vars and found the exact

answer - is that what you're saying?

Thanks.

Kathy

"Enlighten the people generally, and tyranny and oppressions of body

and mind will vanish like evil spirits at the dawn of day," wrote

Thomas Jefferson in 1816

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Received on Mon Jul 31 23:17:06 2006

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