If this floor happens to be slippery, then to conclude that all floors of the same type are also slippery is transferring what is a specific instance to the general casetransferring what is a specific instance to the general case. Honestly not sure of a concise term for it.
My six-year-old has a nine-year-old big brother, and since it's all he knows, he thinks that all families in the entire world have a big brother in it.