The system searches for similarities across the shared database of compared documents, which includes, in addition to the IS AMBIS document server, final theses of participating schools in the Theses.cz system, seminar and other theses in the Odevzdej.cz, system, scientific publications in the Repozitar.cz system and other documents in information systems operated by MU.

Because a significant amount of work and documents are not public, searching the common database is an effective tool for finding possible plagiarism. A student cannot just submit a seminar paper to a friend from another school, because there is a high probability that he is already in the system and there would be similarities. The assignment of seminar and final thesis topics is often repeated, and it is therefore likely that the system will already know about the source documents from which this topic is usually drawn.

The search for similarities also includes an algorithm that analyzes the document being compared and examines it from sources on the Internet. This procedure has various technical limitations and is computationally and time consuming. Therefore, it is preferably used for archives of final theses. Due to the speed of processing, seminar papers in submission offices and long answers in ROPOTs are primarily compared against a shared database of all source documents. This includes, among other things, resources from the Internet, which have been traced in the past for the purpose of checking some of the millions of final theses being compared.

However, there is a difference between finding similarities to seminar papers (for which the shared resource database is used) and final papers (for which the shared resource database is enriched with newly downloaded resources from the Internet). But there is no need to worry, the database is really large, so in most cases the system "knows" enough resources that students usually draw from, as well as enough resources that students usually describe.