A common barrier of entry for taxonomic work is that many species descriptions are published in old and/or cryptic journals that are often only held by the best libraries of the world. The bibliography on our site aims at providing a complete list of all scholarly articles that are relevant to the description of species among the Macrostomorpha and where possible each citation carries an attached PDF file of the article.
In most cases these files were scanned in high quality to PDF (generally from already copied originals) using a copy machine with an built-in document scanner (files ending in _HQ). Lower quality files, for example from a faxed original, have the ending _LQ. These files were then optimized using the default settings of the 'Optimize Scanned PDF' function of Adobe Acrobat Professional (files ending in _HQ_OPT) and then converted into PDFs with searchable text using the built-in 'OCR Text Recognition' function (files ending in _HQ_OPT_OCR). Whenever possible the appropriate primary OCR language was used and the 'Searchable Image (Exact)' output option without downsampling was selected.
In most cases this yields documents in which the recognized text is searchable, but where the files still display the scanned images. This is important, because the quality of the optical character recognition (OCR) process is variable and strongly depends on the quality of the original copy. Due to the sometimes poor quality of the originals not all deposited files are the OCRed version. Moreover, some articles yielded files that are larger that the maximum file attachment size. In these cases they were segmented into separate files and labelled _HQ_OPT_OCR_ppXX-YY (where XX-YY indicates the page range).
You should be careful in concluding that a certain word does not occur in a document if you can't find it when you perform a search on the document. The human eye is still much better at making sense of a low-quality scans than a computer.
Finally, if you have copies or reprints of articles that are not in the bibliography, or if you have a copy of a given article that is of higher quality, please consider contributing it to the site by sending a copy to Lukas Schärer, Evolutionary Biology, Zoological Institute, Vesalgasse 1, 4051 Basel, Switzerland. Alternatively, you can scan it yourself and submit it to the site directly after getting your own account.