Definition editor: elicitation of floating parameters and their priors
A floating parameter relates to a calendar date of interest that does not
bound a group and does not relate to a specific radiocarbon determination.
These are useful in situations where an historical event is known to have
occured during the period of activity under study and to occur before or
after events of interest, but which would otherwise not appear in the project
definition. Examples of such parameters might include, the arrival of a
group of non-indigenous people (such as the Spanish in the Americas), or
the erruption of a volcano.
This page allows you to define floating parameters, along with their
absolute and relative, prior chronological information.
Accessing this page
This page may be accessed from the list
floating parameter information and priors page by selecting "Modify"
for the floating parameter you wish to modify. The page is also shown
when the software needs information about any floating parameters you have
defined. The number of floating parameters you see per page is the
number specified in the configuration page.
Description
This page is split into three sections. The first section allows
you to provide a label for this floating parameter. The label must
be unique.
The second section elicits from you any absolute chronological information
you have about the true calendar date of the floating parameter. BCal allows
you to supply information about the true calendar date in the following
ways. The calendar used to represent such dates will depend on your
setting within the configuration page.
-
An exact year - You must know the exact calendar year for the parameter.
-
A normal distribution of dates - You should know the mean calendar
year and the standard deviation from that year for the true calendar date
for that parameter.
-
A range of calendar years - The real date of the parameter exists
uniformly within this range.
The third section allows you to specify how the floating parameter relates
chronologically to every other parameter within your definition.
This is split into two parts. For each part a list of all the other
parameters is given. You should select, from the list all the parameters
that are known to bound the floating parameter. In the first part
(on the left) you should select all the parameters that are early bounds
of the floating parameter, i.e. bound the parameter and are earlier than
the parameter. In the second part (on the right) you should select
all the parameters that are late bounds of the floating parameter i.e.
bound the parameter and are later than the parameter.
See also
Consistency checking
