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Hauptkomponenten-Analyse (HKA)
Was ist eine Hauptkomponenten-Analyse? Definition einer Hauptkomponenten-Analyse Die Hauptkomponenten-Analyse (engl. Prinicipal Component Analysis, „PCA“) ist eine der am häufigsten verwendeten multivariaten Datenanalysemethoden, mit den man mehrdimensionale Datensätze mit quantitativen Variablen untersuchen kann. Sie wird häufig in der Biostatistik, im Marketing, in der Soziologie und in vielen anderen...
Welch und Brown-Forsythe one-way ANOVA
When to use the Welch and the Brown-Forsythe ANOVA In an analysis of variance, it may happen that the variances cannot be assumed to be equal. In this case, the F test of the ANOVA is not robust enough to be used. XLSTAT offers two alternative tests based on the F distribution but more robust than the classical F test. These tests are: Welch Test or Welch ANOVA (Welch, 1951). The Welch test adjusts...
Dosis-Wirkungs Analyse
What is dose effect analysis Dose effect analysis is simply a Logistic regression (Logit, Probit, complementary Log-log, Gompertz models) used to model the impact of doses of chemical components (for example a medicine or phytosanitary product) on a binary phenomenon (healing, death). Natural mortality in dose effect analysis Natural mortality should be taken into account in order to model the phenomenon...
Analyse von CATA-Daten
What is CATA (check-all-that-apply) analysis? CATA (check-all-that-apply) surveys have become more and more popular for sensory product characterization since 2007, when it was presented by Adams et al. CATA surveys allow to focus on consumers, more representative of the market, instead of trained assessors. They are easy to set up and easy for participants to answer. The principle is that each assessor...
CATATIS
What is CATATIS method and when to use it? The CATATIS method is an improvement of the usual method for processing CATA data. It is considered as the equivalent of the STATIS method for this type of data. The great interest of CATATIS lies in the fact that atypical assessors have a lower weight than those who agree with the rest of the panel. Therefore, the analysis best reflects the general point...
Penalty Analysis
Die penalty analysis (Analyse der Penaliäten, Bestrafungen) ist eine Methode, die in der sensoriellen Analyse zur Identifikation der möglichen Verbesserungsachsen für Produkte in Anschluss an Umfragen bei Kunden oder Experten eingesetzt wird. Die benutzen Daten können zwei Typen darstellen: - Die Präferenzdaten entsprechen Indizes der globalen Kundenzufriedenheit für ein Produkt (zum Beispiel eine...
Erzeuge Wirkungsflächen-Plan
The family of surface response design is used for modeling and analysis of problems in which a response of interest is influenced by several variables and the objective is to optimize this response. Remark: In contrast to this, screening designs aim to study the input factors, not the response value. For example, suppose that an engineer wants to find the optimal levels of the pressure (x1) and the...
Kaplan-Meier Analyse
What is Kaplan-Meier analysis The Kaplan-Meier method, also called product-limit analysis, belongs to the descriptive methods of survival analysis, as does life table analysis. The life table analysis method was developed first, but the Kaplan-Meier method has been shown to be superior in many cases. Kaplan-Meier analysis allows you to quickly obtain a population survival curve and essential statistics...
Überlebenstabelle
What is life table analysis Life table analysis belongs to the descriptive methods of survival analysis, similarly to the Kaplan Meier analysis. The life table analysis method was developed first, but the Kaplan-Meier analysis method has been shown to be superior in many cases. Life table analysis allows to quickly obtain a population survival curve and essential statistics such as the median survival...
Support-Vektor-Maschine (SVM)
Use this method to perform a binary classification, a multi-class classification or a regression on a set of observations described by qualitative and/or quantitative variables (predictors). What is the Support Vector Machine? The Support Vector Machine (SVM) is a supervised machine learning technique that was invented by Vapnik and Chervonenkis in the context of the statistical learning theory (Vapnik...