A unifying quantitative information model is proposed. This model defines information in terms of the attributes of timeliness, precision, and accuracy. Each attribute can be expressed in terms of measurable quantities (metrics). Information is application dependent and is expressed as benefit (utility or value) an attribute imparts to the application. Thus information is a function of timeliness, precision, and accuracy. Statistical values of these attributes can be used to express dependability (i.e. information availability). The purpose of the model is to give quantitative expression to information and system properties, to provide a basis for characterizing system modules, and to stimulate development of analytical techniques for predicting end-to-end quality of service in complex distributed information systems.