Data interpretation univariate methods

Among nonlocal methods, those based on linear projection are the most widely used for data interpretation. Owing to their limited modeling ability, linear univariate and multivariate methods are used mainly to extract the most relevant features and reduce data dimensionality. Nonlinear methods often are used to directly map the numerical inputs to the symbolic outputs, but require careful attention to avoid arbitrary extrapolation because of their global nature. 

Multivariate IQC. Multivariate methods in IQC are still the subject of research and cannot be regarded as sufficiently established for inclusion in the guidelines. The current document regards multianalyte data as requiring a series of univariate IQC tests. Caution is necessary in the interpretation of this type of data to avoid inappropriately frequent rejection of data. 

Data have been collected since 1970 on the prevalence and levels of various chemicals in human adipose (fat) tissue. These data are stored on a mainframe computer and have undergone routine quality assurance/quality control checks using univariate statistical methods. Upon completion of the development of a new analysis file, multivariate statistical techniques are applied to the data. The purpose of this analysis is to determine the utility of pattern recognition techniques in assessing the quality of the data and its ability to assist in their interpretation. 

As our discussions of population distributions and basic statistics have progressed, the use of graphical methods to display data can be seen to play an important role in both univariate and multivariate analysis. Suitable data plots can be used to display and describe both raw data, i.e. original measures, and transformed or manipulated data. Graphs can aid in data analysis and interpretation, and can serve to summarize final results. The use of diagrams may help to reveal patterns in the data which may not be obvious from tabulated results. With most computer-based data analysis packages the graphics support... 

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