The strategic programme is a co-operative programme between Insitute of Marine Research in Bergen and Norwegian Computing Centre; Oslo, and will particularly focus on reducing systematic errors in present survey methodology and to estimate the total uncer tainty in the estimates. The programme will focus its activity in four subtasks: 1): The programme will develop new technology and utilise already established instrumentation for real time, parallel, "off vessel" and on-vessel measurements of fish behaviour during surveying. This includes acoustic buoys, the HUGIN (AUV), and probing transducers. 2): Fish vessel avoidance during standard acoustic surveying will be monitored in large observation series, to be basis for modelling of the reaction pattern of fish during measurement, and for error correction models. 3): Statistical models for small scale, medium and large-scale estimation of uncertainty will be developed for typical pelagic surveys. Realistic inclusion of systemstic errors like avoidance, variability in target strength and trawl sampling efficiency w ill be the main task of this task.