Cost and precision in a stream sampling program

Nomograms relating fixed, variable and total costs (time) to sample size and precision are presented for use in research planning. Time costs for a survey of a Montana, U.S.A., stream were dominated by fixed costs and the laboratory component of variable costs while variable field costs were small. Reductions in both fixed and variable costs influence precision of low-budget survey sampling while reduction of variable costs in large budget research sampling has more effect on total cost than on precision.