by Michiel Bliemer » Thu Aug 22, 2024 7:34 am
In Ngene the default is the swapping algorithm because this is the best algorithm in most cases because it can guarantee attribute level balance. The modified Federov algorithm is useful when the swapping algorithm is unable to generate a design, typically when there are many constraints/prohibitions or dominance constraints imposed.
You could refer to my Handbook chapter:
Bliemer, M.C.J. & Rose, J.M. (2024) Designing and conducting stated choice experiments. In: Hess, S. & Daly, A. (eds) Handbook of Choice Modelling, 2nd edition, Edward Elgar.
It states:
"Several software tools exist containing algorithms to locate efficient designs, including Ngene (ChoiceMetrics, 2018), the ‘%ChoiceEff’ macro in SAS (Zwerina et al., 2010), and the ‘idefix’ package (Traets et al., 2020) in R. Each tool allows the minimisation of the D-error via either a column-swapping algorithm, row-swapping algorithm, and/or a coordinate-swapping algorithm. A coordinate-swapping algorithm such as proposed by Meyer and Nachtsheim (1995) is mainly useful for generating optimal designs without constraints, a column-swapping algorithm (e.g., Huber and Zwerina, 1996) is particularly useful for designs with attribute level balance constraints, and a row-swapping algorithm like the modified Federov algorithm (Cook and Nachtsheim, 1980) is particularly useful for designs with attribute level or dominance constraints."
Michiel