Web service monitoring tools have become an essential component for Service Level Agreement (SLA) because they can collect real quality values of quality attributes to estimate the quality level of services. Since users monitor more than one quality attribute at the same time, quality levels are prone to vary during monitoring time, producing a conflict among quality attributes. In this study, we conduct an empirical study in order to identify potential conflicts among quality attributes during Web services monitoring. For this purpose, we monitor a TravelAgent service in two scenarios: 1) monitoring attributes in isolation, and 2) monitoring attributes in pairs. Bootstrapping is used to estimate the quality level for each scenario, then we compared the quality levels in order to identify degradation. The results have shown that Response Time and Accuracy are the most conflicting attributes during monitoring.