genealogical quests may be generally divided into an ascending and descending line of research:
parents and grandparents are the direct ancestors of a person, that is, after strict mathematical laws 2 parents, 4 grandparents, 8 great-grandparents, 16 great-great grandparents, etc. because each individual has invariably two parents, the calculated number of ancestors doubles with every generation. the number grows to the power of two.
calculating back in time you reach a point when you add up a theoretical number that exceeds the actual number of the population at that point in history. there seems to be a flaw as the mathematical rule is unlikely to be wrong. when you follow the generations back in time you will notice that increasingly several computational positions are taken by a single person: this individual appears in the pedigree chart several times. this phenomenon is entirely natural and does by no means touch the subject of incest. the latter usually only appears once a fair number of generations have passed by.
the person who is the starting point for genealogical research is designated as proband. generally most persons who undertake genealogical research choose as starting point their children or themselves. another frequent point of departure are famous persons. since the number of persons doubles with each generation the research can quickly become boundless. some researchers therefore choose to explore only certain lines. very popular is the research following the eponymous line (typically the all-male ancestral line) or seek to document exclusively the female ancestress.
the representation of genealogical research can be displayed in a list which names the ancestors or it can be represented with the help of a graphic display or a pedigree, which in turn can be decorated or plain. anyone who becomes interested in his own origins and the influences that his or her ancestors may have had on him/her, should turn to genealogy.
the descendents of a person are all the children, grandchildren, great-grandchildren, etc. of a proband. while ancestral research usually sets off from the present to explore the past, it is more likely that lines of descent are traced from a historical person. there is always uncertainty about how many children a person may have had. thus in this line of research one has no certainty that one has found all offspring. while there is no end to ancestors (all persons have parents) a line of descent can end if no children can be found.
popular proves to be the exploration into the offspring of historical celebrities, e.g. the children engendered by emperor charlemagne or niklaus of flue. researchers are often interested in selecting persons from whom they assume to be descended and in whom they are perhaps especially interested in. the focus is often narrowed by selecting only those descendents that passed on a name, or those that have male offspring. such lines of descent are not identical with the complete pool of all descendents of any particular individual since they only represent a certain fraction or a certain line of descent.
the findings of this type of research can either list all descendents in a table or display them in a chart that depicts certain descendents of a person. if the information given is adorned or only shows male descendents, we speak of a family tree.
persons who are more interested in collateral relatives or who want to know all family members carrying a particular and perhaps rare name will engage in this type of research.
mixed forms of research
it is possible to combine both types of research. for instance somebody traces his/her ancestors up to the 16 great-great grandparents and then takes each of these persons as a starting point to search their descendents. in this way one obtains a complex network, which can barely be graphically represented.
a far more complete picture of the ancestors is obtained when the study not only records the direct ancestor of a person but also documents all other children. this allows to explore our ancestors as well as all their siblings, although the descendents of these siblings are generally excluded. occasionally this strategy is also necessary in order to be sure that you have found the correct filiation. we therefore recommend to always document all siblings and to include them into the genealogical studies.
individual forms of research
we already mentioned that genealogical research can extend to a large number of persons. such inflationary tendencies are counter acted by restricting the research focus in various ways. a popular strategy to limit the numbers of persons is the pursuit of a single lineage, e.g. the all-male, the all-female (especially important in jewish traditions), or the eponymous lineage. some family researches restrict the descendants’ number by names, to the descendants in the male line or any other particular characteristic. this results in the documentation of lines of descent (perhaps including siblings) which lead directly to the proband. a house or farm may also serve as a focus since the lineage may show all those who lived on a farm over the course of generations. another alternative is to explore how two people who are not descended from each another, are related through a common ancestor.