title: dd+ - A new dendro software for large data sets and for institutions with archives
Creators: name: Bleicher, Niels
name: Bolliger, Matthias
name: Hafner, Albert
name: Knapp, Hannes
name: Maczkowski, Andrej
name: Nelle, Oliver
name: Oberhänsli, Monika
name: Seifert, Mathias
name: Walder, Felix
Publisher: name: :unas
Year: 2023
Subjects: subject: 020 Library &amp; information sciences
subject: 560 Fossils &amp; prehistoric life
subject: 580 Plants (Botany)
subject: 930 History of ancient world (to ca. 499)
subject: 940 History of Europe

description: Most dendro software packages lack features that are of great importance to long-standing
dendro-institutions with large numbers of samples in their archives and with numerous
datasets on their hard drives. Among these essential features are (i) context information and
metadata for each sample and measurement, (ii) detailed information on the structure and
content of every mean curve, (iii) data consistency, (iv) the definition of subsamples as
dynamic or static, (v) ability to crossdate using thousands of measurements, (vi) provide
output tables for external use such as GIS-systems, (vii) defining roles and rights for different
users, (viii) provide flexible vector graphic export options; and several others.
The new software dd+ covers all these issues. However, it is not meant as an all-in-one
software for dendro studies. Many numeric analyses are better done in R. It rather aims at
providing stability, transparency and consistency for large datasets together with high
performance crossdating tools.
dd+ is a Microsoft server SQL database with in-built dendro features. A SQL querybuilder allows to define subsets and groups based on a wealth of attributes. These groups can
be saved either as dynamic or static list and form the base for browser based management,
editing, correlation or the production of database-tables for external use such as GIS. There
are two browsers for wood samples and two for mean curves, all of which can be used
independently by applying SQL queries or manually picking samples and mean curves.
Calculation procedures are optimised for large datasets. Crossdating 851 vs 1204 series in all
possible synchronous positions takes less than 3 min. Crossdating is assisted by direct visual
presentation of individual pairs which can be set to visible or hidden. dd+ enforces data
consistency by checking your crossdating decisions. Mean curve construction and dating is only
possible if all single crossdating positions are consistent.
By now, dd+ uses the Heidelberg-format and excel-files for import and export.
Knowing about the weaknesses of these formats, they seem helpful for overcoming the many
problems of backward-digitalisation. Once data are entered, the data model opens new
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possibilities. Future development aims at a xml format for data exchange. The latest version
2.6 covers an csv-export in long format for import into R. Meanwhile, the standardisation of
meta data aids in the exchange between labs.
Taking part: dd+ is not open source, but it aims at an open data policy and common
data standards. It has been programmed by professionals in cooperation with the Zurich lab. It
comes without licensing fees, but it is not free of costs: Whoever wants to use dd+, joins the
user community "ArGe dd+" by a contract. All users share the costs of support by a fixed
amount per year. The community decides by simple majority on further development and
improvement projects and the costs are shared. For the moment, dd+ has a focus on managing
samples from historical and archaeological contexts. Future versions will add ecological
aspects.
If you are interested in dd+, please contact niels.bleicher@zuerich.ch.