Ranking
SOWA: Spatial Ordered Weighted Averaging
Makropoulos, C. K., Butler, D. · 2006
Strengths
- •Explicitly models spatially heterogeneous risk attitudes through zone-specific ORness
- •Inherits OWA's full ORness-trade-off flexibility within each zone
- •Reduces to standard OWA (one zone) or WLC (uniform λ=1/n): no discontinuity
- •Counterfactual scores (what-if zone reassignment) are computationally trivial and illustrative
Limitations
- •Zone_order_weights are difficult to elicit: requires domain expert knowledge of spatial risk attitudes
- •Results are sensitive to zone boundary definition
- •Alternatives with extreme criterion profiles (high best, low worst) are most affected by zone ORness: this can appear counter-intuitive
- •Spatial heterogeneity of risk attitudes may be better modelled continuously (e.g. distance-decay ORness) rather than discretely
Method assistant
Grounded explanations: it explains the method, it does not compute.
Assumptions to verify
- •Zone boundaries are meaningful and justified (e.g. hazard zones, administrative districts)
- •Each zone's λ vector correctly encodes the spatial risk attitude of that region
- •Criterion weights w_k are globally applicable (same importance across all zones)
- •Value-scaling to [0,1] is appropriate before aggregation
When not to use
- •Non-spatial problem: alternatives have no zone assignment → use OWA
- •All zones have identical risk attitude → standard OWA is simpler
- •Zone order-weights cannot be elicited from domain knowledge → spatial extension is arbitrary
How to cite
Makropoulos, C. K.; Butler, D. (2006). Spatial ordered weighted averaging: incorporating spatially variable attitude towards risk in spatial multi-criteria decision-making. Environmental Modelling & Software. https://doi.org/10.1016/j.envsoft.2004.10.010