## Hypothesis Testing – Null Hypothesis and Statistical Tests

What is a hypothesis test needed for? A hypothesis test is needed to determine whether there is a significant relationship between two or more variables. To do this, a hypothesis is first made stating that there is such a relationship. Then, data is collected and a statistical test is performed to check the validity of …

## Population and sample size

Population and samples explained A population is a set of objects of interest about which one wishes to make certain statements. A sample is a subset of the population that is selected to make statements about the population. The sample is used to make estimates about the characteristics of the population. The size of the …

## Reliability in statistics

When is a statistic reliable? A statistic is reliable if it produces similar results when used repeatedly. In other words, a reliable statistic is one that leads to similar results across different measurements or analyses. What is reliability in statistics? In statistics, reliability refers to the stability or reliability of a measurement instrument or method. …

## Validity in statistics

When is a statistic valid? Validity in statistics refers to whether a measurement tool or method actually measures what you want to measure. A statistic is valid when it actually measures what you want to measure and is not just an approximation or a distortion of it. There are different types of validity, such as …

## Level of measurement in statistics

Why are there level of measurement? The level of measurement is important because it determines what kind of statistics and analysis can be done. The higher the scale level, the more analysis possibilities there are. What are level of measurements? Scale of measurements refers to the way the values of a variable are measured and …

## Varianz und Kovarianz

Einleitung Varianz in der Statistik Die Varianz ist ein wichtiger statistischer Maßstab, der verwendet wird, um die Streuung der Daten innerhalb einer Gruppe von Werten zu messen. Es gibt eine Beziehung zwischen der Varianz und der StandardabweichungStandardabweichung Die Standardabweichung ist ein Maß für die Streuung der Werte einer Variablen um ihren Mittelwert und gibt an, …