The four criteria for assessing class importance apply to hilltop enclosures as follows:
- Period (currency): Extended. The majority of dates for hilltop enclosures fall between 800 and 500 RCYBC, suggesting that the tradition of building and using sites of this class spanned 300 years. The duration of individual sites may belong to a more restricted period of between 150 and 200 years. The extent to which this represents continuous or sporadic occupation is unknown. This is partly the result of dates which rely upon changes in pottery styles, which are essentially fairly conservative. Although these allow for general chronological statements they are not particularly useful in the construction of more refined schemes. Further limitations are imposed by the small number of securely dated hilltop enclosures. This severly impedes any attempt to pinpoint differential clustering of dates between regions.
- Rarity: Very rare. Between 25 and 30 hilltop enclosures have been recorded. A greater number may exist, but these are likely to represent an early phase in the development of more strongly defended sites of univallate or multivallate form. The discovery of these will depend either upon excavation revealing traces of fairly slight earthworks, or upon the occurence of hilltop enclosure boundaries on a slightly different alignment from their more massive successors.
- Diversity (types): High. Two main types of hilltop enclosure, each sub-divided into three groups according to the structure of the banks, have been identified. The size range, although there is no apparent clustering into distinct groups, is extremely wide (10ha to over 100ha). As Balksbury is the only site where a large area of the interior has been sampled, it is not possible to relate this diversity in form to functional differences.
- Period (representativity): High. Hilltop enclosures are one of a relatively limited number of monument classes characteristic of the early Iron Age.
Assigning scores to these criteria following the system set out in the Monument Evaluation Manual, hilltop enclosures yield a Class Importance Value of 43. This lies just over mid-way up the range of possible values (max = 64). In selecting examples which are of national importance, sites should be included which represent different topographical and geographical locations. A representative sample of each of the types, together with a range of various sizes would also be desirable.