Many attempts have been made at defining family and most have been suc
cessful. By successful I mean here that the definitions have been acce
pted by an important number of followers. But. the definitions have al
l been seriously questioned by others and have in this; respect not be
en successful. Like some others, I stress that there is no family in s
ingular and definite article, there are families, plural and not any d
efinite article. Any group consists of at least two members and I sugg
est that any group be analysed with a dyadic approach. With this appro
ach one can analyse the structure of any family; one can as well study
the existence of emotional ties in the dyadic structure of a family;
one can analyse the power structure in a family by looking at the powe
r structure os all dyads; just to mention some examples of dyadic anal
ysis. This theoretical and analytic tool can be applied not only in re
search but also in, for example, therapy.