The meaning of reability is discussed in contrast to the meaning of validity. While validity of language assesment results refers to the degree of correctness of representation of the language skill being assessed reability of language skill assesment results refers to the degree of preciseness of the representation of the language skill being assesed. The farther the language skills assessment result deviates from the actual level of the skill being assessed the bigger the error is and the lower the reability of the language skills assessment is. Estimating reability means collecting evidence of consistency.