wave-tank data and natural beach data. Certain underlying 

 models, conceptual, physical, and statistical, that apply 

 in the two cases are discussed and in part illustrated. 

 Limited data of the scope necessary for illustration were 

 available from studies designed for other uses at Mission 

 Beach, California, and generalizations derived from analysis 

 of these data are used in discussion of the design of field 

 beach studies seeking to relate beach responses to several 

 complex process elements. 



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