The four criteria for assessing class importance apply to long mounds as follows:
- Period (currency): Long-lived. The tradition of constructing and using long mounds seems to have spanned most of the middle and late Neolithic periods, perhaps a total of over 1000 years.
- Rarity: Very rare. The number of recorded long mounds currently stands at six, but while this probably represents an underestimate of those known the class as a whole is undoubtedly a small one.
- Diversity (form): Low. Two main types of long mound can tentatively be defined on the basis of present evidence.
- Period (representativity): High. Long mounds are one of relatively few classes of monuments that are known from middle and late Neolithic times, and on present showing represent one of the few classes that were current throughout the Neolithic period.
Assigning scores to these criteria following the system set out in the Monument Evaluation Manual, long mounds yield a Class Importance Value of 36. This lies over half-way up the range of possible values (max.= 64) reflecting the rarity but essential homogeneity of the class as a whole. Examples representing both recognizable types, and variations in size, orientation, and position within the landscape, must be included in the sample of nationally important sites. It may also be noted that the proportion of known long mounds that have been excavated means that the number remaining for preservation is fairly small.