In 2005, a new kind of hierarchical clustering method was introduced by Palla et al. that differs in two ways from Ward's method: it can be used on data on which no full similarity matrix is defined and it can produce overlapping clusters, i.e., allow for multiple membership of items in clusters.
This method is especially suitable for biological and chemical data sets where no full similarity measure can be defined and in which multiple membership of items to clusters is expected.
Clustering in this dimension should thus also allow for multiple membership; 3. molecules can carry more than one active group, i.e., pharmacophore, or one characteristic structural feature like heteroaromatic ring systems.
Transnationalism brings to light multiple membership and multiple loyalties – crystallized around dual citizenship – which becomes for immigrants a way to maintain an identity rooted in the home country.
Multiple membership multiple classification (MMMC) multilevel models have been around for some time (3) but are underused in social epidemiology.
See Supplementary Box S1 for more information about the multiple membership analysis technique.
Another major strength of this study is the use of the multiple membership technique.
Specifically, for a sample that had multiple membership labels obtained from different pathways, we applied a simple majority rule to determine the sample's membership.
The inclusion criteria for falling into the category of "other," a category which comprises those not fitting into three major race/ethnicity categories, either because of multiple races, membership in another racial group, or non-response, was not uniform and so minimum and maximum values based on extremes of possible classification schemes were estimated.
