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Regression analysis ordinary least-squares

Deming Regression Analysis and Ordinary Least-Squares Regression Analysis (OLR) (Constant SDs)... [Pg.379]

Traditionally, the determination of a difference in costs between groups has been made using the Student s r-test or analysis of variance (ANOVA) (univariate analysis) and ordinary least-squares regression (multivariable analysis). The recent proposal of the generalized linear model promises to improve the predictive power of multivariable analyses. [Pg.49]

Regression analysis often is used to assess differences in costs, in part because the sample size needed to detect economic differences may be larger than the sample needed to detect clinical differences (i.e., to overcome power problems). Traditionally, ordinary least-squares regression has been used to predict costs (or their log) as a function of the treatment group while controlling for covariables such as... [Pg.50]

Thus whilst an ordinary least squares line may be calculated as a first step in the regression analysis, an elaboration of or an alternative to ordinary least squares regression is needed for most geochemical applications. Some of these alternatives are reviewed below. [Pg.29]

Reduced major axis regression is a more appropriate form of regression analysis for geochemistry than the more popular ordinary least squares regression. The method. (Kermack and Haldane, 1950) is based upon minimizing the areas of the triangles f/ I between points a ... [Pg.29]

In the past few years, PLS, a multiblock, multivariate regression model solved by partial least squares found its application in various fields of chemistry (1-7). This method can be viewed as an extension and generalization of other commonly used multivariate statistical techniques, like regression solved by least squares and principal component analysis. PLS has several advantages over the ordinary least squares solution therefore, it becomes more and more popular in solving regression models in chemical problems. [Pg.271]

Ordinary least squares technique, used for treatment of the calibration data, is correct only when uncertainties in the certified value of the measurement standards or CRMs are negligible. If these uncertainties increase (for example, close to the end of the calibration interval or the shelf-life), they are able to influence significantly the calibration and measurement results. In such cases, regression analysis of the calibration data should take into account that not only the response values are subjects to errors, but also the certified values. [Pg.108]

Ridge regression analysis is used when the independent variables are highly interrelated, and stable estimates for the regression coefficients cannot be obtained via ordinary least squares methods (Rozeboom, 1979 Pfaffenberger and Dielman, 1990). It is a biased estimator that gives estimates with small variance, better precision and accuracy. [Pg.169]

Inhibition constants (K ) are estimated by Dixon plot analysis and linear regression using ordinary least squares. Apparent Km values are estimated by nonlinear regression (Vavricka et al. 2002). [Pg.534]

The goal of this study is to test hypotheses about the relationships between multiple independent variables and one dependent variable. As most of my latent constructs are measured on interval scales and I expect linear relationships between the variables, multiple linear regression analysis with ordinary least squares estimation was used (Cohen 2003 Tabachnick and Fidell 1989). The study had two thematically separate parts the first part is focused on the antecedents of lead usemess of employees in firms (n=83, hypotheses 1-3, dependent variable lead usemess). in the second part, h3 otheses about lead usemess of employees and behavioral outcomes are tested (n=149, hypotheses 4-8, dependent variables innovative work behavior, internal boundaiy spanning behavior, external boundary spanning behavior, organizational... [Pg.136]

Pearson s coefficient of regression, R, and the adjusted R are calculated the same way as in ordinary, least-squares analysis. The same can be said of the F-statistic. [Pg.118]

Model validation would be performed in the similar manner as that for ordinary, least-squares analysis bearing in mind that the computed confidence intervals are only approximate. cannot be used as a measure of performance in nonlinear regression, since the relationship between the sums of squares is no longer orthogonal. [Pg.123]

Most researchers who have worked with discrete event simulation are familiar with classical statistical analysis. By classical, we mean those tests that deal with assessing differences in means or that perform correlation analysis. Included in these tests are statistic procedmes such as t-tests (paired and unpaired), analysis of variance (univariate and multivariate), factor analysis, linear regression (in its various forms ordinary least squares, LOGIT, PROBIT, and robust regression) and non-parametric tests. [Pg.114]

The estimation of RRs is usually performed by ordinary least-square linear regression. This should be done by preferably testing at least six different concentration levels within the linear range plus the blank (if this last exists or it is measurable). To minimize eventual experimental drifts, test samples should be examined in random order (not in order of increasing concentration values). Possibly, standard or test samples should be analyzed in duplicate (or more), especially when it is not possible to analyze at least six standards. If repeating the analysis of some... [Pg.424]

Another problem is to determine the optimal number of descriptors for the objects (patterns), such as for the structure of the molecule. A widespread observation is that one has to keep the number of descriptors as low as 20 % of the number of the objects in the dataset. However, this is correct only in case of ordinary Multilinear Regression Analysis. Some more advanced methods, such as Projection of Latent Structures (or. Partial Least Squares, PLS), use so-called latent variables to achieve both modeling and predictions. [Pg.205]

A statistical algorithm, also known as linear regression analysis, for systems where Y (the random variable) is linearly dependent on another quantity X (the ordinary or controlled variable). The procedure allows one to fit a straight line through points xi, y0, X2,yi), x, ys),..., ( n,yn) where the values jCi are defined before the experiment and y values are obtained experimentally and are subject to random error. The best fit line through such a series of points is called a least squares fit , and the protocol provides measures of the reliability of the data and quality of the fit. [Pg.417]

The adaptive least squares (ALS) method [396, 585 — 588] is a modification of discriminant analysis which separates several activity classes e.g. data ordered by a rating score) by a single discriminant function. The method has been compared with ordinary regression analysis, linear discriminant analysis, and other multivariate statistical approaches in most cases the ALS approach was found to be superior to categorize any numbers of classes of ordered data. ORMUCS (ordered multicate-gorial classification using simplex technique) [589] is an ALS-related approach which... [Pg.100]


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