# Category: Statistics

## How to compare two groups?

Probably one of the most frequently asked questions in statistics is how to compare two groups. We created a video showing a simple example of how to apply Students t-test for this purpose. We compare body height of two groups, women and men. We explain why a t-test is appropriate...

## Statistical Guide for iOS

GSS is a statistical software, which includes not only powerful modules for statistical analyses, but also an intuitive guide, which helps to identify the correct statistical test for your type data and research question. This guide has now been adapted to iOS and is available in the AppStore: GSS for iOS. In the following video we explain, why the statistical guide included in GSS is really an important feature and how the iOS App looks like.

## How does a statistical test work? – Part 2

In the last article, we have illustrated the concept of statistical tests. If you only want to obtain a rough understanding of the concept behind statistical tests then reading our last article is absolutely sufficient. However, if you are interested in more detail, then the following will help you to understand how a p-value is calculated and what “degrees of freedom” means.

## How does a statistical test work? – Part 1

When you do your first statistical tests you may get the impression that doing statistics is complicated. In this article we want to show that the principle of statistical testing is actually relatively simple.

## Derived vs original data?

When presenting the findings of a study people often don’t show the original data that were measured, but they create so called ‘derived data’. Derived data can be: Percentages, rates, rtios, indices, etc.. For example, considering a data set on smoking behaviour, percentages could be used to describe the proportion of smokers in a sample…

## Understanding data type

When you do statistical analyses, the knowledge about data type is very important, because many statistical methods and tests were specifically designed for a specific data type. However, there is a lot of confusion regarding data type, because many different terms are used…

## Selecting statistical tests made easy

Why are there so many tests? If you need to conduct statistical testing for your thesis or your first paper you might be overwhelmed by the large quantity of statistical tests. Why are so many available? How do I choose and how can I be sure to have selected the...

## Dose-response analyses

Overview Dose-response curves are use used to describe the relation of dose (e.g. of a pharmaceutical) and the resulting effect. To do this, dose response functions are fitted to measured data. These functions can then be used to calculate of important benchmarks such as the EC50 (dose leading to 50...