Task: Question Answering
Input (English): Passage: At the time of the site's discovery, there was no was apparent barrow, in part because the ground level of the area had been raised by millennia of hillwash coming down from further up Blue Bell Hill. However, as a result of what is known of this architectural style from better-recorded sites, it is apparent that this stone chamber would have been located at the eastern end of a long earthen barrow. Ashbee noted that this could have reached a length of 55 metres (180 feet). It may be that kerbstones also lined the sides of this barrow, as is evident at several other of the Medway Megaliths; Ashbee suggested that this could have contained as many as 110 or 120 sarsen stones. The monument may have had ditches flanking its sides, and chalk rubble collected in digging these ditches may have been piled up to help form the barrow.During the Early Neolithic, the site may have been close to other chambered long barrows; the White Horse Stone, for instance, is nearby and may have once been part of the chamber of these monuments. Various sarsen stones have been found in the vicinity of both, again perhaps reflecting the remnants of since-destroyed long barrows. To the south of the White Horse Stone was a building — termed "Structure 4806" by its excavators in the 2000s — that was constructed in the Early Neolithic period. Radiocarbon dating from the site suggests a usage date of between 4110-3820 and 3780-3530 calibrated BCE. 18 metres (59 ft) long and 8 metres (26 ft) wide, it was a longhouse of a type known from across various parts of Europe. If it had been a domestic residence, its size would mean that it was only "occupied by a small number of occupants, probably no more than a small family group". A smaller, circular building approximately 3.75 metres (12 ft) in diameter was present just to the south-east of the longhouse; there was little dating evidence for this, but what existed suggested a Late Neolithic origin. The archaeologists who excavated these buildings suggested that they might have been "houses of the living" that were intervisible with the "houses of the dead", including Smythe's Megalith. Alternately, they suggested that the longhouse was "part of the funerary tradition", used in preparing "the remains of the dead or for communal activities such as feasting". 
Question: What type of group of people, and how large, were believed to live in the buildings that were 18 metres long and 8 metres wide?
Output (English): small family group.