The rapid proliferation of streamed audio-visual services to users via the Internet, especially fee-based services, has increased the importance for content providers in establishing, maintaining, improving and validating the quality of service and experience they provide to the subscribers or users of their services. Accordingly, there is provided a method of determining quality metric data at the user's display in response to a provided digital multimedia stream. The quality metric data being stored for subsequent transmission to a remote server for aggregation and correlation with other quality metric data and defect related data of provided digital multimedia streams to provide service and network providers with quantified data relating to the quality of experience of users of Internet based audio-visual services. As such the quality metric data may be applied to discrete or continuous audio-visual content facilitating quality determinations for streamed content.