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.
The CLAMP scoresheet facilitates recording the CLAMP scores as well as automatically calculating the percentage scores that are copied into the reference data sets prior to analysis. As species/morphotype names are entered the scoresheet keeps a running total of the number of taxa.
Scoring is based in the CLAMP leaf character definitions. 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 from being treated 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 the spreadsheet. This should be more than adequate for most fossil sites. If, however, you are fortunate enough to have a really diverse flora contact Bob Spicer for an even larger scoresheet!
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.
The CLAMP scoresheet provides for straightforward scoring. 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. 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. The scoresheet automatically determines the correct values to assign across the different character states. To assign scores by hand is quite complex as can be seen from the character definitions and use of the automated scoresheet is recommended.
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 rules of the classic analysis and should avoid misinterpretation of the scoring protocols. Do not attempt to enter data using the 'Result' sheet.
When all the scoring is complete the values in the pink "percentage score" line on the Result page of the scoresheet should be either:
1) copied and pasted into the reference datasets at the end of the modern site scores for a 'classic' analysis, or
2) used to create a score file for uploading if you are doing an online analysis.