1. A method of evaluating a property of a resource in a block located in an area of land, the method comprising the steps of: a) dividing the area of land into a plurality of blocks; b) obtaining samples from a plurality of sample positions within at least one block of the plurality of blocks; c) providing information concerning the property of the resource for the plurality of sample positions, the information being obtained from analyses of the samples from the sample positions; d) generating a model for a change in the property of the resource along a distance at or within the one block using the provided information; e) calculating parameters associated with the modelled change using Bayes' theorem; f) calculating for the block a property characteristic of the modelled change in the property of the resource using the calculated parameters, the property characteristic being a value based on at least two sample positions within the one block; and outputting the value in order to assist in making a decision related to mining of the resource in the area of land.