Basic probability sampling designs for thematic map accuracy assessment

Choosing a sampling design for assessing thematic map accuracy requires the strength of a sampling design to be matched to the objectives and resources available for the accuracy assessment. The criteria to consider when planning the sampling design are that the sample should: (1) satisfy probability sampling protocol; (2) be simple to implement and analyse; (3) result in low variance for the key estimates of the assessment; (4) permit adequate variance estimation; (5) be spatially well distributed; and (6) be cost effective. Several basic probability sampling designs useful for accuracy assessment are reviewed, and recommendations are provided to guide the selection of an appropriate design.