Statistics for Experimenters: An Introduction to Design, Data Analysis, and Model Building
About: This article is published in Journal of Marketing Research.The article was published on 1979-05-01. It has received 2729 citations till now. The article focuses on the topics: Model building.
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21 Mar 2002TL;DR: An essential textbook for any student or researcher in biology needing to design experiments, sample programs or analyse the resulting data is as discussed by the authors, covering both classical and Bayesian philosophies, before advancing to the analysis of linear and generalized linear models Topics covered include linear and logistic regression, simple and complex ANOVA models (for factorial, nested, block, split-plot and repeated measures and covariance designs), and log-linear models Multivariate techniques, including classification and ordination, are then introduced.
Abstract: An essential textbook for any student or researcher in biology needing to design experiments, sample programs or analyse the resulting data The text begins with a revision of estimation and hypothesis testing methods, covering both classical and Bayesian philosophies, before advancing to the analysis of linear and generalized linear models Topics covered include linear and logistic regression, simple and complex ANOVA models (for factorial, nested, block, split-plot and repeated measures and covariance designs), and log-linear models Multivariate techniques, including classification and ordination, are then introduced Special emphasis is placed on checking assumptions, exploratory data analysis and presentation of results The main analyses are illustrated with many examples from published papers and there is an extensive reference list to both the statistical and biological literature The book is supported by a website that provides all data sets, questions for each chapter and links to software
9,509 citations
TL;DR: In this paper, the complex mechanisms of Fenton and Fenton-like reactions and the important factors influencing these reactions, from both a fundamental and practical perspective, in applications to water and soil treatment, are discussed.
Abstract: Fenton chemistry encompasses reactions of hydrogen peroxide in the presence of iron to generate highly reactive species such as the hydroxyl radical and possibly others. In this review, the complex mechanisms of Fenton and Fenton-like reactions and the important factors influencing these reactions, from both a fundamental and practical perspective, in applications to water and soil treatment, are discussed. The review covers modified versions including the photoassisted Fenton reaction, use of chelated iron, electro-Fenton reactions, and Fenton reactions using heterogeneous catalysts. Sections are devoted to nonclassical pathways, by-products, kinetics and process modeling, experimental design methodology, soil and aquifer treatment, use of Fenton in combination with other advanced oxidation processes or biodegradation, economic comparison with other advanced oxidation processes, and case studies.
3,218 citations
TL;DR: In this article, the properties of FDM parts fabricated by the FDM 1650 were analyzed using a Design of Experiment (DOE) approach, such as raster orientation, air gap, bead width, color and model temperature.
Abstract: Rapid Prototyping (RP) technologies provide the ability to fabricate initial prototypes from various model materials. Stratasys Fused Deposition Modeling (FDM) is a typical RP process that can fabricate prototypes out of ABS plastic. To predict the mechanical behavior of FDM parts, it is critical to understand the material properties of the raw FDM process material, and the effect that FDM build parameters have on anisotropic material properties. This paper characterizes the properties of ABS parts fabricated by the FDM 1650. Using a Design of Experiment (DOE) approach, the process parameters of FDM, such as raster orientation, air gap, bead width, color, and model temperature were examined. Tensile strengths and compressive strengths of directionally fabricated specimens were measured and compared with injection molded FDM ABS P400 material. For the FDM parts made with a 0.003 inch overlap between roads, the typical tensile strength ranged between 65 and 72 percent of the strength of injection molded ABS P400. The compressive strength ranged from 80 to 90 percent of the injection molded FDM ABS. Several build rules for designing FDM parts were formulated based on experimental results.
1,886 citations
TL;DR: Regression analysis provides the most comprehensive sensitivity measure and is commonly utilized to build response surfaces that approximate complex models.
Abstract: Mathematical models are utilized to approximate various highly complex engineering, physical, environmental, social, and economic phenomena. Model parameters exerting the most influence on model results are identified through a ‘sensitivity analysis’. A comprehensive review is presented of more than a dozen sensitivity analysis methods. This review is intended for those not intimately familiar with statistics or the techniques utilized for sensitivity analysis of computer models. The most fundamental of sensitivity techniques utilizes partial differentiation whereas the simplest approach requires varying parameter values one-at-a-time. Correlation analysis is used to determine relationships between independent and dependent variables. Regression analysis provides the most comprehensive sensitivity measure and is commonly utilized to build response surfaces that approximate complex models.
1,636 citations
01 Sep 2006
TL;DR: These data, based on prospective studies of adults, show that all types of IVDs pose a risk of IVD-related BSI and can be used for benchmarking rates of infection caused by the various types of intravascular devices in use at the present time.
Abstract: OBJECTIVE: To better understand the absolute and relative risks of bloodstream infection (BSI) associated with the various types of intravascular devices (IVDs), we analyzed 200 published studies of adults in which every device in the study population was prospectively evaluated for evidence of associated infection and microbiologically based criteria were used to define IVD-related BSI. METHODS: English-language reports of prospective studies of adults published between January 1, 1966, and July 1, 2005, were identified by MEDLINE search using the following general search strategy: bacteremia [Medical Subject Heading, MeSH] OR septicemia [MeSH] OR bloodstream infection AND the specific type of intravascular device (eg, central venous port). Mean rates of IVDrelated BSI were calculated from pooled data for each type of device and expressed as BSIs per 100 IVDs (%) and per 1000 IVD days. RESULTS: Point incidence rates of IVD-related BSI were lowest with peripheral intravenous catheters (0.1%, 0.5 per 1000 IVDdays) and midline catheters (0.4%, 0.2 per 1000 catheter-days). Far higher rates were seen with short-term noncuffed and nonmedicated central venous catheters (CVCs) (4.4%, 2.7 per 1000 catheter-days). Arterial catheters used for hemodynamic monitoring (0.8%, 1.7 per 1000 catheter-days) and peripherally inserted central catheters used in hospitalized patients (2.4%, 2.1 per 1000 catheter-days) posed risks approaching those seen with short-term conventional CVCs used in the intensive care unit. Surgically implanted long-term central venous devices—cuffed and tunneled catheters (22.5%, 1.6 per 1000 IVD-days) and central venous ports (3.6%, 0.1 per 1000 IVD-days)—appear to have high rates of infection when risk is expressed as BSIs per 100 IVDs but actually pose much lower risk when rates are expressed per 1000 IVD-days. The use of cuffed and tunneled dual lumen CVCs rather than noncuffed, nontunneled catheters for temporary hemodialysis and novel preventive technologies, such as CVCs with anti-infective surfaces, was associated with considerably lower rates of catheter-related BSI. CONCLUSIONS: Expressing risk of IVD-related BSI per 1000 IVDdays rather than BSIs per 100 IVDs allows for more meaningful estimates of risk. These data, based on prospective studies in which every IVD in the study cohort was analyzed for evidence of infection by microbiologically based criteria, show that all types of IVDs pose a risk of IVD-related BSI and can be used for benchmarking rates of infection caused by the various types of IVDs in use at the present time. Since almost all the national effort and progress to date to reduce the risk of IVD-related infection have focused on short-term noncuffed CVCs used in intensive care units, infection control programs must now strive to consistently apply essential control measures and preventive technologies with all types of IVDs.
1,299 citations
References
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TL;DR: In this article, it has been shown that a rapid estimate of o may be obtained from the mean value of the range, which is only slightly less accurate than the estimate obtained from sum of squares.
Abstract: STARTING from the contribution of Tippett (1925), a considerable amount of computational work has been carried out in recent years with the object of making possible the use of range, i.e. the distance between the highest and lowest observation, when dealing with samples from a normal population. Thus Tippett's tables of the mean range expressed in terms of the population standard deviation, o', for sample sizes n = 2 to 1000 have been republished in Tables for Statisticians and Biometricians, Part II, Table XXII (K. Pearson, 1931). Later E. S. Pearson (1932) gave a table containing the standard deviation of range, and also the approximate upper and lower 10, 5, 1 and 0 5 % probability levels for sample sizes n = 2 to 100, again in terms of o as unit. In doing this he used empirical Pearson-type curves with correct moments, and checked his results against some experimental sampling distributions. If a number of small samples are available, it has been shown that a rapid estimate of omay be obtained from the mean value of the range, which is only slightly less accurate than the estimate obtained from the sums of squares. Again, owing to the high correlation between range and standard deviation in a sample of size 10 or less, it was pointed out by Pearson & Haines (1935) that range may be usefully substituted for standard deviation in control charts used to study changes in the variation of quality in industry. In all these cases, however, the basic sampling distribution used has been that of the ratio of range to O. Not very long ago " Student " (the late Mr W. S. Gosset) suggested to Prof. E. S. Pearson that it might be useful to know more about the sampling distribution of the ratio q = w/s,
544 citations
125 citations
TL;DR: A bibliography of papers on multiple comparisons between 1966 and 1976 is contained, which includes a discussion of some of the more important developments during this period.
Abstract: This article contains a bibliography of papers on multiple comparisons between 1966 and 1976. A discussion of some of the more important developments during this period precedes the bibliography.
118 citations