Monitoring of calibration equation performance is essential if high quality of predicted analytical data is to be sustained. In this paper we outline and illustrate the use of some statistical methods which are well suited for post-prediction data scrutiny. Mean square prediction error is partitioned into three components, viz. mean bias, systematic bias and random error. Reproducibility measures such as concordance correlation (rc), intraclass correlation (r2) and correlation between difference and sum (r(X – Y)(X + Y)) are also discussed. Other topics discussed include the maximisation of R2, type II regression (both variables with error model) and new graphical displays.
DhanoaM.S.BarnesR.J. and ListerS.J., Report: Forage Quality Analysis by Near Infrared reflectance Spectroscopy.Commission of the European Communities, Directorate General for Agriculture (1988).
2.
ListerS.J., Determination of silage composition using near infrared reflectance spectroscopy. PhD Thesis, University of Reading (1995).
3.
TheilH., Applied Economic Forecasting., North Holland Publishing Company, Amsterdam (1966).
4.
BibbyJ. and ToutenburgH., Prediction and Improved Estimation in Linear Models.John Wiley & Sons (1977).
5.
HaitovskyY., The American Statistician23, 20 (1969).
6.
DhanoaM.S.ListerS.J. and BarnesR.J., Proceedings of XVIIth International Biometric Society Conference., Hamilton, Canada (1994).
7.
HamiltonD., The American Statistician41, 129 (1987).
8.
CuadrasC.M., The American Statistician47, 256 (1993).
9.
BertrandP.V. and HolderR.L., The Statistician37, 371 (1988).
10.
CooleyW.W. and LohnesP.R., Multivariate Data Analysis., John Wiley & Sons, New York (1971).
McGrawK.O. and WongS.P., Psychological Methods1, 30 (1996).
15.
MorganW.A., Biometrika31, 13 (1939).
16.
PitmanE.J.G., Biometrika31, 9 (1939).
17.
AltmanD.G. and BlandJ.M., The Statistician32, 307 (1983).
18.
GrubbF.E., Journal of the American Statistical Association43, 243 (1948).
19.
ThompsonW.A., Journal of the American Statistical Association58, 474 (1963).
20.
ShuklaG.K., Biometrics29, 373 (1973).
21.
MaloneyC.J. and RastogiS.C., Biometrics26, 671 (1971).
22.
JaechJ.L., Biometrics27, 1097 (1971).
23.
KinsellaA., The Statistician35, 421 (1986).
24.
ListerS.J. and DhanoaM.S., Journal of Agricultural Science Cambridge131, 237 (1998).
25.
BarnesR.J.DhanoaM.S. and ListerS.J., Appl. Spectrosc.43, 772 (1989).
26.
WilliamsP.C. and NorrisK.H., Near Infrared Technology in the Food and Agricultural Industries.American Association of Cereal Chemists, St. Paul, Minnesota, USA (1987).
27.
GoedhartP.W., Netherlands Journal of Agricultural Science38, 449 (1990).
28.
ParkR.S.GordonF.J.AgnewR.E.BarnesR.J. and SteenR.W.T., Animal Feed Science and Technology68, 235 (1997).
29.
DhanoaM.S.SandersonR. and FranceJ., Proceedings of British Society of Animal Science (1997).
