The External Class Description (ECD) measures the absolute external comprehensibility of a class, taking into account the methods interface and the class attributes;
Class CoGnitive Index (CCGI) measures the ratio between ECD and CC (with all weights = 1), giving a relative value for the understandability of the class.
Another aspect, related to class complexity is class comprehensibility or understandability.
The External Class Description (ECD) metric gives a measure of the complexity of the external interface of methods and attributes. It measures what the user understand by looking at the header file (that are normally the only library part available).
ECD alone doesn’t give a good evaluation of class comprehensibility because is not related to the total complexity of the class.
In our framework Class CoGnitive Index (CCGI) metric has been defined in order to solve this problem. In this metric all the weight of CC are 1 in order to be compared with ECD.