# Introduction

There are three principal factors lying in the base of genealogy:

1. A person's name (who?).
2. Location—where an event occurred (where?).
3. Date of an event (when?).

Using GEDKeeper you can process large amounts of genealogical data. The main consideration here is that GEDKeeper honors these three main factors. For example, one can quickly find all namesakes, or all people from the same community, or everyone who lived in a specific period of time. You can filter data using all the three factors. For example, to select namesakes, who lived in the same community in the specified year.

You collect information (create a database) using different sources (including archives of all kinds). The following are two main sources: censuses and registers of births. Other sources are also possible, but we take these two sources as a basic.

A database filled with entries from sources may be counted as conditionally complete one. For example, we have data defining all citizens of a specific locality at a specific period of time—if we had used censuses. Later we were adding more and more new information, and finally we created a huge data array with many people living in several locations during different times. Such a database is very useful for a genealogist, because no one knows about relations between people in the database beforehand. This becomes more obvious later, after inspecting other sources, for example, registers of births.

Why is database called conditionally complete? Because it does not contain strictly accurate data. Many data are approximate, or even estimated. For example, a date in database can be exact (1954.06.12), or much less exact (1954), or approximate (around 1976), or estimated (before 1956 or after 1873). It is very important for the software to handle such dates correctly.

GEDKeeper has a very efficient tool called "Timeline" plugin. This tool can make time samples for events. Using "Timeline" one can get a model of the original source—an archival document. For example, after we have made a time sample for 1858 using locations of events, we can get a list like the original source —people who lived in a specific community in 1858 (as in the tenth census of 1858). This allows us to check the validity of all the data we have added to the database.