They knew there was something there – possibly a biggish island like New Guinea, possibly a mass of smaller islands like the East Indies – and they called this amorphous entity New Holland, but none equated it with the long-sought southern continent.
In his book "In a Sunburned Country," Bill Bryson discusses the European perception of a vast landmass in the southern hemisphere, referred to as New Holland. There was speculation about its size and nature, whether it was a large island akin to New Guinea or a collection of smaller islands like those in the East Indies. This ambiguity reflected the limited understanding of Australia's geography during that time.
Despite the name New Holland, there was a disconnect between the European imagination and the reality of the region. The explorers did not associate this area with the elusive southern continent they had long sought, highlighting a period of exploration characterized by both curiosity and misunderstanding about the geography of the southern seas.