Abundance Schemes

An abundance scheme provides a semi-quantitative equivalent or alternative to numerical counting of specimens in a sample, allowing estimates of abundance to be made.

Example

This section of dialog shows an abundance scheme called the Default Abundance Scheme. It has 5 classes. When this scheme is used to record occurrences, the analyst can record 'abundant' to represent anywhere between 15 and 50 occurrences of one taxon. The Abundant class is represented by 'A' wherever it is used. Where the count is used in calculations, for example to calculate the numerical equivalent for plotting a histogram on a chart, or for finding a group total, the output value of 15 is used.

Abundance Schemes and Analyst Suites

Abundance Schemes are associated with Analysis Suites. This means that if there is more than one suite of analyses for a discipline in a well, each can have a different abundance scheme. You do not have to assign any abundance scheme to a suite if you are going to record your data numerically, but if you subsequently need to record semi-quantitative data in the suite, a scheme can be retrospectively assigned. You could also assign a scheme retrospectively in order to see a semi-quantitative view of quantitative data in the biostratigraphy panel.

To see which schemes are assigned to which analyst suites or change associations, open the Analysis Suites dialog from the Analyses tab in the Samples and Interpretations module.

Abundance Schemes dialog

This dialog displays a list of all the abundance schemes in the database. Open it from the control panel (Config menu), Samples & Interpretations module (File menu) or Analysis Suites dialog.

Use the buttons to Add... or Edit... a scheme using the Abundance Scheme: Add/Edit dialog, or Delete an Abundance Scheme.

If you Delete a scheme, the system checks whether that scheme is associated with any Analysis Suites in any of your wells. If it is, you will be asked if you want to carry out a further check on whether semi-quantitative data are recorded in those wells. If there are no taxon occurrences which use the scheme then it is safe to delete the scheme. You are not allowed to delete a scheme if it has been used; you must delete the related analyses first.

The Show wells... button enables you to see in which wells each abundance scheme has been used (see below).

The Find similar button will check to see if there are any similar abundance schemes in case you want to merge schemes.

Find Similar

Similarity is based on the number of classes in the schemes, the class abbreviations and the minimum number assigned to each class.

Schemes similar to the selected scheme will be displayed in the Abundance Schemes: Merge dialog. To merge any of the listed schemes highlight them and then press the Merge button. The scheme in the list will disappear from the database, and analysis suites that previously referenced those schemes will be updated with the replacement scheme.

If there are no similar schemes a warning message to this effect will be displayed.

Show wells (Abundance Scheme Usage dialog)

This dialog displays a list of wells and analysis suites where the abundance scheme has been used.

The well name is shown with the well code in brackets, followed by the discipline, analyst and suite number.

The list contains entries where the scheme has been assigned to the suite, irrespective of whether there are occurrences in the suite which have been recorded using the scheme.

The Edit... button opens the Well Abundance: Edit dialog. Use this to reassign the suite and/or the sample occurrences to a different scheme, or to explore the scheme to determine the number of times each entry in the scheme has been used in the analysis suite.

Page last updated: 05-Dec-2014 9:16