Strategies for the incremental inference of majority-rule sorting - - PowerPoint PPT Presentation
Strategies for the incremental inference of majority-rule sorting - - PowerPoint PPT Presentation
Alexandru OLTEANU Lab-STICC, Universit Bretagne Sud, France 23/11/2018 DA2PL 2018 Poznan, Poland Strategies for the incremental inference of majority-rule sorting models alexandru.olteanu@univ-ubs.fr a) direct elicitation: DM gives model
Context
MCDA guides the DM through a decision aiding process.
?
Decision Situate Formulate Select and tune a model Solve
Model tuning a) direct elicitation: DM gives model parameters; b) indirect elicitation: parameters are inferred from holistic judgments given by the DM (assignment examples);
- one-shot or incremental elicitation;
- assignment examples are selected or constructed;
Alexandru OLTEANU Strategies for the incremental inference of MR-Sort 1/12
Context
MCDA guides the DM through a decision aiding process.
?
Decision Situate Formulate Select and tune a model Solve
MR-Sort
- ordinal classification, or sorting;
- criteria weights wj;
- majority threshold λ > 1
2;
- k categories and k−1 profiles;
- a∈ch ifg aSbh−1 and a /
Sbh Model tuning a) direct elicitation: DM gives model parameters; b) indirect elicitation: parameters are inferred from holistic judgments given by the DM (assignment examples);
- one-shot or incremental elicitation;
- assignment examples are selected or constructed;
Alexandru OLTEANU Strategies for the incremental inference of MR-Sort 1/12
Context
MCDA guides the DM through a decision aiding process.
?
Decision Situate Formulate Select and tune a model Solve
Model tuning a) direct elicitation: DM gives model parameters; b) indirect elicitation: parameters are inferred from holistic judgments given by the DM (assignment examples);
- one-shot or incremental elicitation;
- assignment examples are selected or constructed;
Alexandru OLTEANU Strategies for the incremental inference of MR-Sort 1/12
Context
MCDA guides the DM through a decision aiding process.
?
Decision Situate Formulate Select and tune a model Solve
Model tuning a) direct elicitation: DM gives model parameters; b) indirect elicitation: parameters are inferred from holistic judgments given by the DM (assignment examples);
- one-shot or incremental elicitation;
- assignment examples are selected or constructed;
Alexandru OLTEANU Strategies for the incremental inference of MR-Sort 1/12
The protocol
Model inference Updated MR-Sort model Decision maker Generate alternatives Elicitation Assignment examples
Research question: Can we develop a strategy to reduce the amount of information required from the DM ?
Alexandru OLTEANU Strategies for the incremental inference of MR-Sort 2/12
The protocol
Model inference Updated MR-Sort model Decision maker Generate alternatives Elicitation Assignment examples
Research question: Can we develop a strategy to reduce the amount of information required from the DM ?
Alexandru OLTEANU Strategies for the incremental inference of MR-Sort 2/12
Proposed strategies for generating alternatives
Strategies for generating assignment examples
Random (RND)
- a ∶ gj(a) ∼ U(minj,maxj), ∀j ∈ J
Non-dominated same category random (NDR)
- if
x y ch s t gj x gj a gj y then a is rejected;
Alexandru OLTEANU Strategies for the incremental inference of MR-Sort 3/12
Strategies for generating assignment examples
Random (RND)
- a ∶ gj(a) ∼ U(minj,maxj), ∀j ∈ J
Non-dominated same category random (NDR)
- if ∃x,y ∈ ch s.t. gj(x) ⩾ gj(a) ⩾ gj(y) then a is rejected;
Alexandru OLTEANU Strategies for the incremental inference of MR-Sort 3/12
Strategies for generating assignment examples
Fixing limit profiles (FLP)
- we use the model inferred from the previous iteration;
- we try to bound each profile from above and below;
Minimal majority coalition of criteria: J J
j J
wj and i J
j J i
wj (1) Maximal minority coalition of criteria: J J
j J
wj and i J J
j J i
wj (2)
Alexandru OLTEANU Strategies for the incremental inference of MR-Sort 4/12
Strategies for generating assignment examples
Fixing limit profiles (FLP)
- we use the model inferred from the previous iteration;
- we try to bound each profile from above and below;
Minimal majority coalition of criteria: J + = {J+ ⊆ J∣ ∑
j∈J+
wj ⩾ λ and ∀i ∈ J+, ∑
j∈J+−{i}
wj < λ} (1) Maximal minority coalition of criteria: J − = {J− ⊆ J∣ ∑
j∈J−
wj < λ and ∀i ∈ J − J−, ∑
j∈J−∪{i}
wj ⩾ λ} (2)
Alexandru OLTEANU Strategies for the incremental inference of MR-Sort 4/12
Strategies for generating assignment examples
Fixing limit profiles (FLP)
Alexandru OLTEANU Strategies for the incremental inference of MR-Sort 5/12
Strategies for generating assignment examples
Fixing limit profiles (FLP)
Alexandru OLTEANU Strategies for the incremental inference of MR-Sort 5/12
Strategies for generating assignment examples
Fixing limit profiles (FLP)
Alexandru OLTEANU Strategies for the incremental inference of MR-Sort 5/12
Strategies for generating assignment examples
Fixing limit profiles (FLP)
Alexandru OLTEANU Strategies for the incremental inference of MR-Sort 5/12
Strategies for generating assignment examples
Fixing limit profiles (FLP)
Alexandru OLTEANU Strategies for the incremental inference of MR-Sort 5/12
Strategies for generating assignment examples
Fixing limit profiles (FLP)
Alexandru OLTEANU Strategies for the incremental inference of MR-Sort 5/12
Strategies for generating assignment examples
Fixing limit profiles (FLP)
Alexandru OLTEANU Strategies for the incremental inference of MR-Sort 5/12
Strategies for generating assignment examples
Fixing limit profiles using a central model (FLP+)
- identical to FLP except that the model inferred from the
previous iteration is centered within the search space;
Alexandru OLTEANU Strategies for the incremental inference of MR-Sort 6/12
Strategies for generating assignment examples
Fixing limit profiles using a central model (FLP+)
- identical to FLP except that the model inferred from the
previous iteration is centered within the search space;
x
Alexandru OLTEANU Strategies for the incremental inference of MR-Sort 6/12
Strategies for generating assignment examples
Fixing limit profiles using a central model (FLP+)
- identical to FLP except that the model inferred from the
previous iteration is centered within the search space;
x x x x
Alexandru OLTEANU Strategies for the incremental inference of MR-Sort 6/12
Strategies for generating assignment examples
Fixing limit profiles using a central model (FLP+)
- identical to FLP except that the model inferred from the
previous iteration is centered within the search space;
x x x
Alexandru OLTEANU Strategies for the incremental inference of MR-Sort 6/12
Proximity of two MR-Sort models
Distance between criteria importance parameters dC = 1 2m ⋅ ∑
i∈1..m
∑
J′∈(J
i)
dJ
′
C , where
(3) dJ
′
C =
⎧ ⎪ ⎪ ⎪ ⎪ ⎪ ⎪ ⎪ ⎪ ⎪ ⎨ ⎪ ⎪ ⎪ ⎪ ⎪ ⎪ ⎪ ⎪ ⎪ ⎩ , if ∑
j∈J′ w
′
j ⩾ λ
′ and ∑
j∈J′ w
′′
j ⩾ λ
′′
- r ∑
j∈J′ w
′
j < λ
′ and ∑
j∈J′ w
′′
j < λ
′′
1 , otherwise (4) Distance between category profiles importance parameters dP = 1 (k − 1) ⋅ m ⋅ ∑
h∈1..k−1
∑
j∈J
∣gj(b
′
h) − gj(b
′′
h)∣
(5)
Alexandru OLTEANU Strategies for the incremental inference of MR-Sort 7/12
Experimental validation
Experimental framework
- m ∈ {3,4}
- k ∈ {2,3}
- nin = 4
- nst ∈ {1,4}
- nte = 10,000
- 50 models for each
- config. of m, k, nst
Alexandru OLTEANU Strategies for the incremental inference of MR-Sort 8/12
Retrieving the original model
10 60 0.85 0.90 0.95 1.00 20 24 45 28 FLP+ FLP NDR RND ∣Ai∣ Classification accuracy 3 criteria, 2 categories 10 90 0.85 0.90 0.95 1.00 46 78 85 53 FLP+ FLP NDR RND ∣Ai∣ Classification accuracy 3 criteria, 3 categories 10 100 0.85 0.90 0.95 1.00 36 45 62 41 FLP+ FLP NDR RND ∣Ai∣ Classification accuracy 4 criteria, 2 categories 140 0.85 0.90 0.95 1.00 71 80 107 FLP+ FLP NDR RND ∣Ai∣ Classification accuracy 4 criteria, 3 categories FLP+ FLP+ NDR+ RND+
Alexandru OLTEANU Strategies for the incremental inference of MR-Sort 9/12
Distance measures
10 20 30 40 50 60 0.1 0.2 0.3 0.4 0.5 ∣Ai∣ dB 3 criteria, 2 categories 10 20 30 40 50 60 70 80 90 0.1 0.2 0.3 0.4 0.5 ∣Ai∣ dB 3 criteria, 3 categories 10 20 30 40 50 60 70 80 90 100 0.1 0.2 0.3 0.4 0.5 ∣Ai∣ dB 4 criteria, 2 categories 10 20 30 40 50 60 70 80 90 100 110 120 130 140 0.1 0.2 0.3 0.4 0.5 ∣Ai∣ dB 4 criteria, 3 categories FLP+ FLP+ NDR+ RND+
Alexandru OLTEANU Strategies for the incremental inference of MR-Sort 10/12
Conclusions and perspectives
Conclusions and perspectives
Conclusions:
- Proposed strategies provide better results than the
classical approach: FLP+ ≻ {FLP,NDR} ≻ RND
- Results currently only for small problem instances;
- Correlation between distance measures and model
convergence; Perspectives:
- Extend to larger instances (metaheuristics);
- New strategies (e.g. order FLP alternatives based on
distance from targeted profile);
- Select vs. generate alternatives? Assignment errors?