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Screening designs

What are screening designs The family of screening designs aims for the study of the effect of two or more factors. In general factorial designs are the most efficient for this type of study. But the number of necessary tests is often too large when using factorial designs. There are other possible types of designs in order to take into account the limited number of experiments that can be carried...

Partitioning Around Medoids

The PAM algorithm searches for k representative objects in a data set (k medoids) and then assigns each object to the closest medoid in order to create clusters. Its aim is to minimize the sum of dissimilarities between the objects in a cluster and the center of the same cluster (medoid). It is known to be a robust version of k-means as it is considered to be less sensitive to outliers. The Partitioning...

Price Sensitivity Meter (Van Westendorp)

What is Price Sensitivity Meter? This version of price sensitivity analysis (and its impact on sales volume and revenue) is due to Van Westendorp and was presented at the ESOMAR Congress in 1976. It was later enriched by Newton et al. in 1993, to respond to mainstream criticism that this previous method did not take purchase intention into account. This method consists of conducting a survey on a...

ROC curves

The ROC curve generated by XLSTAT allows to represent the evolution of the proportion of true positive cases (also called sensitivity) as a function of the proportion of false positives cases (corresponding to 1 minus specificity), and to evaluate a binary classifier such as a test to diagnose a disease, or to control the presence of defects on a manufactured product. What is a ROC curve? The ROC...

Penalty analysis in Excel tutorial

MaxDiff analysis in Excel tutorial

ROC curve analysis in Excel tutorial

Nelson-Aalen analysis in Excel tutorial

Statistical Power to compare variances

Statistical Power analysis for the comparison of variances in XLSTAT XLSTAT includes several tests to compare variances such as the test of comparison of the variances of two samples. XLSTAT can calculate the power or the number of observations required for a test based on Fisher's F distribution to compare variances. When testing a hypothesis using a statistical test, there are several decisions...

Inter-laboratory proficiency testing

What is inter-laboratory proficiency testing? Proficiency testing, also called interlaboratory comparison, involves using statistical methods to compare the performance of several participants (which may be laboratories, inspection bodies, or individuals), referred to as “items” in XLSTAT, for specific measurements (referred to as “tests” in XLSTAT). Proficiency testing can be performed to assess...