The four criteria for assessing class importance apply to large irregular stone circles as follows:
- Period (currency): Long-lived. The tradition of constructing large irregular stone circles probably started in the Late Neolithic and continued through to the end of the Early Bronze Age, a total duration of perhaps fifteen centuries.
- Rarity: Very rare. About 37 examples are currently known, although excavation of stone circles may reveal more which belong to the class.
- Diversity (form): Medium. Four main types can be identified on the basis of the presence or absence of associated features, outlying standing stones, centre stones, embankments, portal stones, and combinations of these.
- Period (representativity): High. Large irregular stone circles are one of relatively few classes of Late Neolithic and Early Bronze Age monument. They are widely distributed and probably relate to more than one function and have a wide variety of associations suggesting that they were fairly important places in the lives of prehistoric communities.
Assigning scores to these criteria following the system set out in the Monument Evaluation Manual, large symmetrical stone circles yield a Class Importance Value of 45. This lies two thirds of the way up the range of possible values (max. = 64), reflecting the long currency and extreme rarity of the class. Examples representing the main types and those not yet disturbed should be included in the sample of nationally important sites. The number of extant examples is few so choice will be limited.