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Verification level. Neither model has been field tested. Hypothetical data sets were generated (Tables 3 and 4) and used to test the assumptions that HSI's obtained by using the models are reasonable and acceptable. Eighteen striped bass experts/authorities, who participated in a Delphi exercise to develop striped bass habitat suitability information (Crance 1985), reviewed a draft of this paper. The reviewers provided substantial ideas and suggestions that were incorporated, where appropriate, into the model building effort. Field use of models. The level of detail for a particular model applica- tion depends on time, money, and accuracy constraints. Detailed field sampling of all of the variables that affect striped bass habitat will provide the most reliable and replicable HSI's. Use of previously collected data for any of the variables may result in satisfactory application of the models. Tempera- ture, dissolved oxygen, and stream velocity data required for the models are likely to have been published or be available from natural resource agencies. Suggested techniques for measuring model variables and references to consult for more details are listed in-Table 5. Subjective estimates of any or all variables can be made in order to reduce the amount of time required to apply the models. When subjective estimates are used, they should be made or confirmed by experienced striped bass experts. Use of subjective estimates decreases reliability and replicability and should be accompanied by appro- priate documentation on the method of HSI determination and quality of the data used in the models. Interoretina Model Outouts Initially, the objective is that the HSI's for striped bass habitat obtained using the models are correlated with an expert's ranking. Ideally, HSI outputs would have a direct linear relationship to carrying capacity. This relationship is assumed but has not been tested. The proper interpretation of the model output is one of comparison. Habitats with high HSI's would, on the average, be expected to have higher standing crops of striped bass or the potential to support more striped bass than those with a lower HSI. The correlation between population size and HSI has not been tested. Factors not included in the HSI models may have a signif- icant effect on population size. The models cannot be expected to discriminate among different habitats with high resolution at this stage of development because they depend on untested assumptions and known oversimplifications. Interactions among model variables and species both play a role in determining habitat suitability for striped bass; however, these influences are not considered in the model. It is suggested that the HSI outputs be interpreted as indicators or predictors of high (0.8 to 1.0), medium (0.5 to 0.7), low (0.2 to 0.4), or unsuitable (0.0 to 0.1) striped bass habitat. Neither model will provide an HSI of 1.0 if any model component is not within the optimum value for the life stage being considered. 20