Järpe, Eric2011-02-182011-02-181998-03-010349-8034http://hdl.handle.net/2077/24547Surveillance to detect changes of spatial patterns is of interest in many areas such as environmental control and regional analysis. Here the interaction parameter of the Ising model, is considered. A minimal sufficient statistic and its asymptotic distribution are used. It is demonstrated that earlier results on surveillance of a normally distributed random variable can be used for interesting cases. Properties such as expected delay and false alarm are examined for some examples.40engText