Some contradictions in attribute combinations

[Mayaba]

Hi Michiel,

I made some changes from the last time I posted some questions; I changed my syntax to relax some level combinations. However, it seems like I'm still struggling to have a breakthrough on this. Please guide me on any other method to avoid contradictions in attribute combinations/levels?


Design
;alts = A*, B*, C*, D*, None
;rows = 12
;block = 3, minsum
;eff = (mnl,d)
;alg = mfederov
;reject:

A.production = 3 and A.mortality = 0,
B.production = 3 and B.mortality = 0,
C.production = 3 and C.mortality = 0,
D.production = 3 and D.mortality = 0,

A.production = 3 and A.mortality = 1,
B.production = 3 and B.mortality = 1,
C.production = 3 and C.mortality = 1,
D.production = 3 and D.mortality = 1,

A.production = 3 and A.mortality = 2,
B.production = 3 and B.mortality = 2,
C.production = 3 and B.mortality = 2,
D.production = 3 and D.mortality = 2,

A.production = 2 and A.mortality = 0,
B.production = 2 and B.mortality = 0,
C.production = 2 and B.mortality = 0,
D.production = 2 and D.mortality = 0,

A.production = 2 and A.mortality = 1,
B.production = 2 and B.mortality = 1,
C.production = 2 and B.mortality = 1,
D.production = 2 and D.mortality = 1,

A.production = 2 and A.mortality = 3,
B.production = 2 and B.mortality = 3,
C.production = 2 and B.mortality = 3,
D.production = 2 and D.mortality = 3,

A.production = 1 and A.nestingperches&scratching = 1,
B.production = 1 and B.nestingperches&scratching = 1,
C.production = 1 and C.nestingperches&scratching = 1,
D.production = 1 and D.nestingperches&scratching = 1

;model:

U(A) = bnestingperches&scratching.dummy [0.133] * nestingperches&scratching [1,0] + bmortality.dummy[-0.120|-0.134|0.245] * mortality [3,2,1,0] + bproduction.dummy [0.863|0.345|-0.126] * production[3,2,1,0]
+ bprice[-0.47] * price[4 ,6,8,10](3-5,3-5,3-5,3-5)
/
U(B) = bnestingperches&scratching * nestingperches&scratching + bmortality * mortality + bproduction * production + bprice * price /
U(C) = bnestingperches&scratching * nestingperches&scratching + bmortality * mortality + bproduction * production + bprice * price /
U(D) = bnestingperches&scratching * nestingperches&scratching + bmortality * mortality + bproduction * production + bprice * price /
U(None) = b0[-3]
$

[Michiel Bliemer]

What contradictions do you get? Could you give an example of a contradicting choice task?

[Mayaba]

Hi Michiel,

The levels for the attributes are as follows:

1. Nestingperches&scratching = (1) Present and (0) Absent

2. Production = (1) Battery cages, (0) Colony cages, (2) Barn and (3) Free range

3. Mortality = (3) High, (2) Medium, (0) Low and (1)Very low

Note: The numbers in brackets are levels I have used. Below are the details from one of the choice sets. Sorry I could not figure out how to paste a choice set in a table format.


1. Nestingperches
Absent - Choice A
Present - Choice B
Absent - Choice C
Present - Choice D

2. Mortality
High - Choice A
Medium - Choice B
Low - Choice C
Medium - Choice D

3. Production
Free range - Choice A
Colony - Choice B
Barn - Choice C
Battery - Choice D

4. Price
$10.5 - Choice A
$8.5 - Choice B
$6.5 - Choice C
$4.5 - Choice D


With the constraints in the syntax, choice A should not have absent level, choice B should not have medium level choice C should not have low and absent levels and choice D should not have medium level.

[Michiel Bliemer]

Your choice task is:

A.nestingperches&scratching = 0, A.mortality = 3, A.production = 3, A.price = 10.5
B.nestingperches&scratching = 1, B.mortality = 2, B.production = 0, B.price = 8.5
C.nestingperches&scratching = 0, C.mortality = 0, C.production = 2, C.price = 6.5
D.nestingperches&scratching = 1, D.mortality = 2, D.production = 1, D.price = 4.5

These attribute levels do not violate any of your constraints. For example, for choice A, the only constraint you have on nestingperches&scratching is:
reject: A.production = 1 and A.nestingperches&scratching = 1

This constraint means that level 1 for nestingperches&scratching should not occur at the same time as level 1 for production.

Since A.production = 3 = 3 and A.nestingperches&scratching = 0, these levels do not violate your constraint and hence Absent (level 0) is fine according to your constraints. So if you still encounter unrealistic attribute level combinations, please have a close look at your constraints and define them correctly.

Michiel

[Mayaba]

Dear Michiel,

Thank you for the quick response. I will go through the constraints again, I may have missed something.