Statistics
Articles
Trees that grow from tables
When stepping outside the domain of distributive and descriptive statistics for individual variable…
Is gambling addictive? What if the respondent has no opinion?
The standard approach to investigating a single categorical variable involves a few elements.
Three ways to perceive reliability
When measuring a phenomenon, you need to select the right tool. To measure temperature, you use a t…
Reduction of multidimensionality
Is a simple two-dimensional coordinate system always enough for us?
How to prepare for reliability analysis?
The area of reliability analysis is of interest first of all to those who plan to use scales and in…
Deciding to remove an item from the scale
Sometimes instead of asking a single question in a survey, we ask a whole set of questions, which a…
Perceptual maps: choosing the correct normalization method
In this article you can find perceptual maps prepared using different normalization methods.
Correspondence analysis: solution quality assessment
Correspondence analysis is a technique often thought of as an alternative to a crosstab (contingenc…
SNA or network as an analytical object
Today, we will look into Social Network Analysis (SNA), or Social Relation Analysis.
How to boost a decision tree algorithm
The decision tree is a popular and effective algorithm used primarily in classification work, but i…
Consumer shopping value analysis using regression trees. Part 1
How can we estimate the potential value of consumer shopping, predict the behavior of a visitor to …
Car value: variable selection for linear modelling
The Automatic linear modeling procedure is intended to streamline the work of analysts who use regr…
Multidimensional scaling in brand positioning
Positioning a product in the context of the competition, or the identification of a product’s featu…
Consumer shopping value analysis using regression trees. Part 2
Regression trees are a very interesting data analysis technique commonly used in tasks related to p…
Scatter plot
A scatterplot (also otherwise known as a dot plot or scatterplot) is a graph with two perpendicular…
Factor analysis
The aim of factor analysis is to explain as much of the variability as possible with as few variabl…
The power of a test
The power of a test is the probability of detecting a statistically significant effect when one act…
From variance to the method of least squares
The mean is one of the most popular and widely used statistical measures. By itself, it is not an e…
Student T-tests
The Student's t-test group is used to compare two groups of results, measured by the arithmetic mea…
Pearson's chi-square independence test
The chi-square test of independence is one of the most common statistical tests. It is used to test…
Quantiles, quartiles, percentiles (measures of location)
We use quantiles to determine the position of a given value compared to others in a group or popula…
Skewness and kurtosis
Kurtosis and skewness are measures of asymmetry that describe properties such as the shape and asym…
Logistic regression
Regression is used to predict the value of the dependent (predictor) variable on the basis of the v…
Pearson's chi-square correlation test
Popular statistical tests include Pearson's chi-square tests. It is worth noting at the outset that…
Levels of measurement
The level of measurement is one of the most important properties of variables. It determines which …
Outlier cases. Identification and significance in data analysis
In data analysis, it is important to identify unusual observations that are significantly different…
Statistical inference
Statistical inference is the branch of statistics through which it becomes possible to describe, an…
Recoding quantitative variables into qualitative ones – techniques and their practical application
When analysing the data, we take into account both quantitative information (such as salary, age, n…
Segmentation: from grouping to classification
Segmentation is a key process in data analysis, dividing a data set into relatively homogeneous gro…
The three sigma rule
The three sigma rule is an important tool in statistics and quality management. In the context of d…