I have not done a pilot study and we know the order of preference of all but b6 (the lower the number, the greater the preference).

The minimum number of rows is 15, so I plan to double it to 30 questions.

In this case, what is the required sample size?

S estimate is over 10,000, so I need at least 10,000?

- Code: Select all
`Design`

;alts = alt1*, alt2*

;rows = 30

;eff = (mnl, d)

;alg = mfederov(stop=total(1000000 iterations))

;model:

U(alt1) = b1.dummy[-0.01] * A[1,0]

+ b2.dummy[-0.01|-0.02] * B[1,2,0]

+ b3.dummy[-0.01|-0.02] * C[1,2,0]

+ b4.dummy[-0.01|-0.02] * D[1,2,0]

+ b5.dummy[-0.01] * E[1,0]

+ b6.dummy[0|0|0] * F[1,2,3,0]

/

U(alt2) = b1 * A

+ b2 * B

+ b3 * C

+ b4 * D

+ b5 * E

+ b6 * F

$