Essential components of a BioBrowser session

Modgen components

Before using BioBrowser, it is important for the analyst to understand some of the essential components of Modgen.

database (.mdb) files
These files are created by Modgen during the simulation phase of the model.  They contain the raw data necessary to construct the graphical representation created by BioBrowser.  Although the database files can be read by BioBrowser, BioBrowser can never modify the contents of these files.  All BioBrowser sessions begin by opening a pre-existing database file.

dominant actors
These elements are at the core of any Modgen simulation exercise.  Dominant actors are usually persons or households which are created at the beginning of the simulation process and undergo changes to their characteristics as they proceed through their lives.  Dominant actors are defined by their characteristics (states) and by the events which transform their states.

non-dominant actors
Modgen simulates one case at a time where a set of dominant actors undergoes changes to its states.  One possible change to a person actor’s state is a marriage or a common-law union.  When this event has occurred, Modgen generates an appropriate spouse.  This spouse, another person actor, is termed a non-dominant person actor.  Once created, non-dominant actors undergo the same possible events as the dominant actors of the same type.  Non-dominant actors are linked to their dominant actor.

tentative actors
The process of generating a non-dominant actor in Modgen involves generating a sequence of potential candidates.  The candidates who are not chosen are termed tentative actors since they have no links to any of the dominant actors in the model.

states
These elements define the characteristics of the actors over the span of their lifetimes.  Examples of states might include age, employment status, or educational attainment.  States can be scalars or arrays.

Before beginning to use BioBrowser, a database file needs to be created using Modgen. If you want to examine states which are not in the database, a new Modgen simulation must be run and a new database file needs to be created.  A sample database demo(trk).mdb was included with this software package.  For more information on creating new databases in Modgen please refer to the Modgen Developer's Guide or, for a quick overview/refresher, see Appendix: Creating a new Modgen database file.

BioBrowser components

BioBrowser takes the database and creates graphics of the characteristics of the actors.  In addition to the above Modgen concepts, there are other concepts which relate specifically to BioBrowser.

biography (.bbr) files
These files contain the graphical representations which the analyst has created during a BioBrowser session.  The biography files can be created, saved, and edited by the analyst during a BioBrowser session.

display band
The graphical display of a state or linked actor.

filter
The criteria used to narrow or refine the set of actors to be used in a biography..

navigation band
A type of display band which also includes a set of buttons which allows the user to go from the display bands of one actor to another and add new states to the biography.  The buttons resemble the control buttons on the front of a CD player.