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Journal ArticleDOI

Probit Analysis (3rd ed).

01 Jan 1972-Applied statistics (JSTOR)-Vol. 21, Iss: 2, pp 210
About: This article is published in Applied statistics.The article was published on 1972-01-01. It has received 3368 citations till now. The article focuses on the topics: Probit model.
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TL;DR: The median-effect principle and its mass-action law based computer software are gaining increased applications in biomedical sciences, from how to effectively evaluate a single compound or entity to how to beneficially use multiple drugs or modalities in combination therapies.
Abstract: The median-effect equation derived from the mass-action law principle at equilibrium-steady state via mathematical induction and deduction for different reaction sequences and mechanisms and different types of inhibition has been shown to be the unified theory for the Michaelis-Menten equation, Hill equation, Henderson-Hasselbalch equation, and Scatchard equation. It is shown that dose and effect are interchangeable via defined parameters. This general equation for the single drug effect has been extended to the multiple drug effect equation for n drugs. These equations provide the theoretical basis for the combination index (CI)-isobologram equation that allows quantitative determination of drug interactions, where CI 1 indicate synergism, additive effect, and antagonism, respectively. Based on these algorithms, computer software has been developed to allow automated simulation of synergism and antagonism at all dose or effect levels. It displays the dose-effect curve, median-effect plot, combination index plot, isobologram, dose-reduction index plot, and polygonogram for in vitro or in vivo studies. This theoretical development, experimental design, and computerized data analysis have facilitated dose-effect analysis for single drug evaluation or carcinogen and radiation risk assessment, as well as for drug or other entity combinations in a vast field of disciplines of biomedical sciences. In this review, selected examples of applications are given, and step-by-step examples of experimental designs and real data analysis are also illustrated. The merging of the mass-action law principle with mathematical induction-deduction has been proven to be a unique and effective scientific method for general theory development. The median-effect principle and its mass-action law based computer software are gaining increased applications in biomedical sciences, from how to effectively evaluate a single compound or entity to how to beneficially use multiple drugs or modalities in combination therapies.

4,270 citations

Journal ArticleDOI
TL;DR: An integrated approach to fitting psychometric functions, assessing the goodness of fit, and providing confidence intervals for the function’s parameters and other estimates derived from them, for the purposes of hypothesis testing is described.
Abstract: The psychometric function relates an observer’s performance to an independent variable, usually some physical quantity of a stimulus in a psychophysical task. This paper, together with its companion paper (Wichmann & Hill, 2001), describes an integrated approach to (1) fitting psychometric functions, (2) assessing the goodness of fit, and (3) providing confidence intervals for the function’s parameters and other estimates derived from them, for the purposes of hypothesis testing. The present paper deals with the first two topics, describing a constrained maximum-likelihood method of parameter estimation and developing several goodness-of-fit tests. Using Monte Carlo simulations, we deal with two specific difficulties that arise when fitting functions to psychophysical data. First, we note that human observers are prone to stimulus-independent errors (orlapses). We show that failure to account for this can lead to serious biases in estimates of the psychometric function’s parameters and illustrate how the problem may be overcome. Second, we note that psychophysical data sets are usually rather small by the standards required by most of the commonly applied statistical tests. We demonstrate the potential errors of applying traditionalX2 methods to psychophysical data and advocate use of Monte Carlo resampling techniques that do not rely on asymptotic theory. We have made available the software to implement our methods.

2,263 citations

Book
11 Jul 2019
TL;DR: The aim of the present paper is to provide an overview of state-of-the-art dose-response analysis, both in terms of general concepts that have evolved and matured over the years and by means of concrete examples.
Abstract: Dose-response analysis can be carried out using multi-purpose commercial statistical software, but except for a few special cases the analysis easily becomes cumbersome as relevant, non-standard output requires manual programming. The extension package drc for the statistical environment R provides a flexible and versatile infrastructure for dose-response analyses in general. The present version of the package, reflecting extensions and modifications over the last decade, provides a user-friendly interface to specify the model assumptions about the dose-response relationship and comes with a number of extractors for summarizing fitted models and carrying out inference on derived parameters. The aim of the present paper is to provide an overview of state-of-the-art dose-response analysis, both in terms of general concepts that have evolved and matured over the years and by means of concrete examples.

1,827 citations


Cites background or methods from "Probit Analysis (3rd ed)."

  • ...For the important special case where α1 = α2 the ratio is referred to as the relative potency [11], and it is interpreted as a measure for quantifying the strength of one substance over another, i....

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  • ...The model fits may then be compared using the anova()method; see again Example 3 in S1 File....

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  • ...PLOSONE | DOI:10.1371/journal.pone.0146021 December 30, 2015 8 / 13 In case several dose-response curves are fitted simultaneously the function compParm() is useful for comparisons between groups within a single model parameter; see Example 3 in S1 File....

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  • ...For instance, various special cases may be derived from the general four-parameter log-logistic model function [26] (see also Example 4 in S1 File)....

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  • ...The response may also be discrete as in number of events observed in a specific time interval such as number of juveniles, offspring, or roots [10]; this setting also encompassses Wadley’s problem considered in Example 6 in S1 File [11]....

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01 Jan 1998
TL;DR: In this paper, the authors examined the semantics of thermal comfort in terms of thermal sensation, acceptability, and preference, as a function of both indoor and outdoor temperature, as predicted by the adaptive hypothesis.
Abstract: The adaptive hypothesis predicts that contextual factors and past thermal history modify building occupants' thermal expectations and preferences. One of the predictions of the adaptive hypothesis is that people in warm climate zones prefer warmer indoor temperatures than people living in cold climate zones. This is contrary to the static assumptions underlying the current ASHRAE comfort standard 55-92. To examine the adaptive hypothesis and its implications for Standard 55-92, the ASHRAE RP-884 project assembled a quality-controlled database from thermal comfort field experiments worldwide (circa 21,000 observations from 160 buildings). Our statistical analysis examined the semantics of thermal comfort in terms of thermal sensation, acceptability, and preference, as a function of both indoor and outdoor temperature. Optimum indoor temperatures tracked both prevailing indoor and outdoor temperatures, as predicted by the adaptive hypothesis. The static predicted means vote (PMV) model was shown to be partially adaptive by accounting for behavioral adjustments, and fully explained adaptation occurring in HVAC buildings. Occupants in naturally ventilated buildings were tolerant of a significantly wider range of temperatures, explained by a combination of both behavioral adjustment and psychological adaptation. These results formed the basis of a proposal for a variable indoor temperature standard.

1,747 citations


Cites background or methods from "Probit Analysis (3rd ed)."

  • ...The ensemble insulation value differs by as much as 20% depending on whether one uses the tables and algorithms in the older or newer versions of ASHRAE Standard 55 (1981, 1992), or ISO 7730 (1994). It will therefore be important that rigorous statistical correction factors are used to create consistent ensemble clo values across the RP-884 database. 2. Accounting for the chair insulation. The tendency for PMV to overestimate thermal neutralities has been reported in several field studies (Schiller 1990), prompting Fanger and Wyon (1990) to suggest that the method of estimating clothing insulation might be systematically flawed by omission of the thermal effect that chairs have on their occupants. McCullough and Olesen (1994) responded by examining the effects of upholstered office furniture on the total thermal insulation of a heated manikin, and found that a typical office chair adds approximately 0....

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  • ...The net result is that adapted building occupants may be perfectly comfortable at temperatures beyond those recommended in standards such as ASHRAE 55 (1992) and ISO 7730 (1984, 1994)....

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  • ...• Class I: Field experiments in which all sensors and procedures were in 100% compliance with the specifications set out in ASHRAE Standard 55 (1992) and ISO 7730 (1984). In particular, all of the shortcomings identified in Class II investigations were absent from Class I field experiments....

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  • ...For example, when recently asked by a union official whether or not Standard 55 (ASHRAE 1992) was applicable to un-air-conditioned premises, ASHRAE’s Technical Committee (TC 2.1) responsible for the standard openly declared that their comfort charts were intended for both HVAC and naturally ventilated premises. Many researchers, however, challenge this assumption of universal applicability, arguing that it ignores important contextual differences that can attenuate responses to a given set of thermal conditions. While the “comfort zone” might be viewed by the engineering community as a design goal for a deterministic HVAC control system, its relevance to naturally ventilated buildings where conditions are inherently much more variable is questionable (Forwood 1995). This was also acknowledged by Givoni (1992), who revised his already notable work on the building bioclimatic chart....

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  • ...The ensemble insulation value differs by as much as 20% depending on whether one uses the tables and algorithms in the older or newer versions of ASHRAE Standard 55 (1981, 1992), or ISO 7730 (1994). It will therefore be important that rigorous statistical correction factors are used to create consistent ensemble clo values across the RP-884 database. 2. Accounting for the chair insulation. The tendency for PMV to overestimate thermal neutralities has been reported in several field studies (Schiller 1990), prompting Fanger and Wyon (1990) to suggest that the method of estimating clothing insulation might be systematically flawed by omission of the thermal effect that chairs have on their occupants....

    [...]

Journal Article
TL;DR: In this paper, the adaptive hypothesis predicts that contextual factors and past thermal history modify building occupants' thermal expectations and preferences, which is contrary to static assumptions underlying the current ASHRAE comfort standard 55-92.
Abstract: The adaptive hypothesis predicts that contextual factors and past thermal history modify building occupants' thermal expectations and preferences. One of the predictions of the adaptive hypothesis is that people in warm climate zones prefer warmer indoor temperatures than people living in cold climate zones. This is contrary to the static assumptions underlying the current ASHRAE comfort standard 55-92. To examine the adaptive hypothesis and its implications for Standard 55-92, the ASHRAE RP-884 project assembled a quality-controlled database from thermal comfort field experiments worldwide (circa 21,000 observations from 160 buildings). Our statistical analysis examined the semantics of thermal comfort in terms of thermal sensation,

1,455 citations