Washington Administrative Code
Title 434 - Secretary of State
Chapter 434-379 - Initiatives and referenda
Section 434-379-010 - Random sampling procedure

(1) Take a minimum three percent random sample of the signatures submitted;

(2) Check each signature sampled to determine the number of valid signatures in the sample, the number of signatures in the sample which are invalid because the individual signing is not registered to vote or the signature is improper in form, and the number of signatures which are duplicated in the sample;

(3) Calculate an allowance for the chance error of sampling by multiplying the square root of the number of invalid signatures in the sample by 1.5;

(4) Estimate the upper limit of the number of signatures in the population which are invalid by dividing the sum of the invalid signatures in the sample and the allowance for the chance error of sampling by the sampling ratio, i.e., the number of signatures sampled divided by the number of signatures submitted;

(5) Determine the maximum allowable number of pairs of signatures in the population by subtracting the sum of the number of signatures required by Article II, Section 1 of the Washington state Constitution and the estimate of the upper limit of the number of invalid signatures in the population from the number of signatures submitted;

(6) Determine the expected number of pairs of signatures in the sample by multiplying the square of the sampling ratio by the maximum allowable number of pairs of signatures in the population;

(7) Determine the acceptable number of pairs of signatures in the sample by subtracting 1.65 times the square root of the expected number of pairs of signatures in the sample from the expected number of pairs of signatures in the sample;

(8) If the number of pairs of signatures in the sample is greater than the acceptable number of pairs of signatures in the sample, each signature shall be canvassed to determine the exact number of valid signatures;

(9) If the number of pairs of signatures in the sample is less than the acceptable number of pairs of signatures in the sample, the petition shall be deemed to contain sufficient signatures and the serial number and ballot title shall be certified to the state legislature as provided in RCW 29A.72.230 or to the county auditors as provided in RCW 29A.72.250.