Splitweighing and standardisation using the SpliwStan2.out program:
21 september 2023

Input is file Composed_Dflip_ed
One output file is created, for example JS1567_archaeo__4Ch_d_Spw

The Input file Composed_Dflip_ed is created first with KeelWidth13, from which the output is fed to the DexFlip program for deflip corrections.
The output from DexFlip is file Composed_Dflip, which then is edited manually to add the splitweight numbers (NSPL) into the first column.

NSPL indicates the number of times a record line is listed (according to within sample splitweighting between size fractions and accounting for uneven sample splits across samples.




Some explanations:
Splitweighting (correction for unequal splits between size fractions within a sample):

For efficiency reasons sometimes unequal sample splits between size fractions within a sample were imaged and analyzed.

For example: Only 1 specimen was found in the entire split (1/1 split) of the 250-1000 microns size fraction, while exceedingly many specimens were found in the 125-250 microns and 63-125 microns size fractions. In such a case, for example only 1/4 was used from the 125-250 microns and 63-125 microns fractions.

For subsequent calculation of statistics (means, medians, etc) it is therefore necessary to compensate for using different splits between size fractions of a sample. In the present example this was compensated by listing the measurements from the 250-1000 mu fraction (1/1 split) 1x (NSPL=1), while measurements from the smaller size fractions (1/4 split each) were listed 4x (NSPL=4) for importing the data into a statistics program.



Standardisation (correction for unequal sample split numbers across samples:
This correction occurs after Splitweighting within samples was accomplished. In our Cipero Coast study we decided to account for
unequal sample splits across samples by up-scaling (standardizing) each sample to the entire (1/1) split. For example: If in sample X 1/1 split was imaged and analysed and in sample Y only 1/4 split was used, then the measurements from sample Y was listed 4x prior to importing the data into a statistis program.

In program SplitwStan the split number NSPL (first column of input file) is considered to represent the combined effect of splitweighting and standardisation.

