Evaluation ot Physical Chemistry Student Data Fortran programs have been written which.analyze the data of a number of common physical chemistry experiments, as an aid in the evaluation of student results. Mast of the programs make use of a subroutine ("FIT"), which computes the lesst-squares fit of the data to the equation f(x) = A. + AIX A2X2, where any of the coefficients may be constrained to zero, as appropriate for the problem. When Aa is unconstrained, the coordinate axes are transposed to the data cluster during computation, t o avoid raund-off error. Points with excessively large deviations are rejected successively until either no deviation exceeds "H"times the standard deviation of the remaining set, or 20% of the points have been rejected. " Hdefaults to 2.0 if not specified in the range 1.1-9.0. (This rejects -10% of the points in a normal distribution.) Input for each of any number of data sets is up to 20 data points plus appropriate experimental parameters, studert results, and identification codes. Output varies with the experiment, but usually includes number of points rejected, standard deviation, calculated result(s), student result(s) and discrepancy. Where facilities permit, the programs could be used by students to confirm (or not) their own calculations. More detailed information is available to those interested, and program listings with sample output are available an loan.
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David P. Pearson Oregon Graduate Center Beaverton, 97005
Volume 50, Number 3, March 1973
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