Scoresheets

Photograph of Morus showing variation in leaf size and shape

Remember to score the full range of leaf size and shape!

Broussonetia papyifera (L.) L'Hert.ex Vent displays a particularly striking range of leaf form. Note: the leaf in the top left of the image has an apex damaged by insect attack.

CLAMP operates using a well defined set of scoring protocols. Leaf characters (traits) for individual species are scored numerically and scores for aggregates of species at any one location, or any one fossil assemblage, are combined into a leaf trait spectrum unique to that location or assemblage. Scoring and generation of the leaf trait spectrum is done by means of a CLAMP Scoresheet that has embedded within in it the scoring protocols.

The basic CLAMP scoresheet facilitates recording the CLAMP scores as well as automatically calculating the percentage scores that are copied into the reference datasets prior to analysis. When you download this file it will open on the 'Scoresheet' sheet. You can check this by looking at the tab at the bottom of the sheet. This is the sheet that you enter data on. As species/morphotype names are entered the scoresheet keeps a running total of the number of taxa.

Scoring is simplified by entering '1' if a character is present. Where a leaf character is not present it is allocated '0' - do not enter '0' just leavel the cell blank. This scoresheet automatically determines the correct values to assign across the different character states. At the bottom of the 'scoresheet' sheet is a 'Result' tab that shows your data automatically converted to the form required by CLAMP. The values you see here are calculated according to the CLAMP rules. Do not attempt to enter data using the 'Result' sheet.

Any character category (e.g the margin character set, the size character set etc.) that does not contain any score for a given taxon is regarded as missing data. A typical situation in which this might arise is that all specimens for a given taxon might have the apex destroyed so no score is possible for the apex group of character states. In this instance the percentage scores are calculated not from the total number of taxa scored but the total number minus the number of taxa in that character state group for which there is no data. This prevents missing data being scored as zero. The only category for which this is not true is the "lobed" category. If there is insufficient information in the specimens to determine if they are lobed or not then it is likely there is insufficient material to provide a reliable score.

A maximum of 100 species can be scored in Scoresheet_2010. This should be more than adequate for most fossil sites. If, however, you are fortunate enough to have a really diverse flora you can use the larger Scoresheet_2010_300 which can accommodate up to 300 species.

The scoresheet incorporates a "completeness statistic". This is unity when all character states for all morphotypes have a score. If any data are missing the statistic drops below 1. In general scoresheets in which the completeness statistic is below 0.6 are likely to lead to an unreliable CLAMP result.

When all the scoring is complete the values in the pink "percentage score" line should be used to create a score file for uploading if you are doing an online analysis.

Download the CLAMP Scoresheet_2010 (176kb)

Download the CLAMP Scoresheeet_2010_300 (468kb)