An Improved Exact Algorithm for Least-Squares Unidimensional Scaling

Table 5

Relative performance of the tests.

Instance	B & B			BB3
	Sym.	Dom.	UB	Sym.	Dom.	UB
p20	11.58^a	88.24^b	0.18^c	11.11^a	88.73^b	0.16^c
p25	8.86^a	90.87^b	0.27^c	8.48^a	91.43^b	0.09^c
p30	7.01^a	92.84^b	0.15^c	6.29^a	93.64^b	0.07^c
M26	11.40^a	88.47^b	0.13^c	10.44^a	89.52^b	0.04^c
J28	8.55^a	89.23^b	2.22^c	5.68^a	94.26^b	0.06^c
F20	8.01^a	75.63^b	16.36^c	13.25^a	85.42^b	1.33^c
F25	7.04^a	81.27^b	11.69^c	10.31^a	89.39^b	0.30^c
F30	8.95^a	83.91^b	7.14^c	7.74^a	92.16^b	0.10^c
F35	8.53^a	87.23^b	4.24^c	—^a	—^b	—^c
M36	8.82^a	91.14^b	0.04^c	—^a	—^b	—^c

aPercentage of partial solutions fathomed due to symmetry test.
bPercentage of partial solutions fathomed due to dominance test.
cPercentage of partial solutions fathomed due to bound test.