In deed they are Nic. However, as Subjunction Zone has previously pointed out to you, assumptions are not just literally assumed. There are techniques to test and verify that those assumption are valid. Dating a rock or organic material is not just blindly dated with an assumption that there is no contamination or excess daughter isotopes present. There are very precise methods for detecting any contamination and quantifying it if it exists. What you see in the creation science literature is extracts from actual dating method text books where "assumptions" are itemized. This is so students can understand what must be understood, accounted for and quantified. What the creation science material does not reveal is the methods and techniques that are used to validate those assumptions. Again, that is my problem with creation science. What is the purpose of deliberately misleading how actual dating techniques work? To me, and I am a not only a Christian, but a contributing church member,and I am quite troubled with that community that sees the need to misrepresent well known and understood science. That tells me that their interpretation of the bible is lacking faith. Otherwise why would they do it?