The Spearman correlation, also called rank correlation, is a statistical method for measuring the strength and direction of a monotonic relationship between two variables. Unlike the Pearson correlation, which measures the linear relationship between variables, the Spearman correlation examines the monotonic relationship, which can also be described as non-linear. It is often used in social …
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 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 …
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. …
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 …
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 …
What is the normal distribution? The normal distribution, also known as the Gaussian normal distribution or bell curve, is an important distribution in statistics and occurs in many different applications. It describes a symmetrical distribution in which the data are distributed around a mean value (the arithmetic mean). The normal distribution has a characteristic course …
Introduction Reliability analysis provides information on how reliable an analysis is. It describes the extent to which a procedure measures identically when performed repeatedly. If I run my experiment a second time, will comparable results come out? If the answer is “no” it means: we have a problem. Perfect reliability, on the other hand, means …
Linearity in statistics An important requirement for performing calculations in SPSS is linearity between the dependent variable and the independent variables. Linearity states that the relationship between the variables is linear, meaning that the change in the dependent variable is proportional to the change in the independent variable. If linearity is not present, the results …
What is multiple linear regression? Multiple linear regression is a technique for modeling the relationship between a dependent variable (also called the target variable) and multiple independent variables (also called predictors). Multiple linear regression is used to estimate a linear relationship between variables and predict how the dependent variable will change based on changes in …