Statistics How To

Distance Sampling > What is Line Intercept Sampling? In line-intercept sampling (also known as line transect sampling*), an element is included in a sample from a particular region if a certain line segment (called a transect) intersects the element. One way to choose the transect is to select a baseline, then run the transect perpendicular … Read more

Sampling in Statistics > What is Distance Sampling? Distance sampling is a catch-all term to describe a range of methods to estimate the density of biological populations using measured distances to individuals in the population. It can also be used to estimate the abundance of inanimate objects like birds’ nests or animal burrows. This type … Read more

Bias > Non Response Bias What is Non Response Bias? Non response happens when there is a significant difference between those who responded to your survey and those who did not. This may happen for a variety of reasons, including: Some people refused to participate. This could be because you are asking for embarrassing information, … Read more

Statistics Definitions > Unidimensionality What is Unidimensionality? “Unidimensionality” is used to describe a specific type of measurement scale. A unidimensional measurement scale has only one (“uni”) dimension. In other words, it can be represented by a single number line. Some examples of simple, unidimensional scales: Height of people. Weight of cars. IQ. Volume of liquid. … Read more

Non normal distribution > The Maxwell-Boltzmann Distribution What is the Maxwell-Boltzmann distribution? The Maxwell-Boltzmann distribution is a probability distribution mainly used in physics and statistical mechanics. The distribution, which describes the kinetic energy of air particles in a particular sample, was devised by James C. Maxwell and Ludwig Boltzmann. In simple terms, the kinetic energy … Read more

Probability Distributions > Burr Distribution What is the Burr Distribution?   The Burr distribution (also called the Burr Type XII distribution or Singh–Maddala distribution) is a unimodal family of distributions with a wide variety of shapes. It is obtained by transforming a Pareto distribution, raising it to a positive power. Restricting the Burr distribution’s parameters … Read more

Probability Distributions > Nakagami Distribution What is the Nakagami Distribution? The Nakagami distribution (also called the Nakagami-m or Nakagami-μ distribution) is a fairly new probability distribution, first appearing in 1960. It is a generalized way to model small scale fading for dense signal scatters and it one of the most common distributions for modeling right-skewed, … Read more

Design of Experiments > Control Group What is a Control Group? The control group (sometimes called a comparison group) is used in an experiment as a way to ensure that your experiment actually works. It’s a way to make sure that the treatment you are giving is causing the experimental results, and not something outside … Read more

Statistics Definitions > Statistical Conclusion Validity You may find it helpful to read this article first: Reliability and Validity in Research. What is Statistical Conclusion Validity? Statistical Conclusion Validity(SCV), or just Conclusion Validity is a measure of how reasonable a research or experimental conclusion is. For example, let’s say you ran some research to find … Read more

Statistics Definitions > External Validity External Validity Definition External validity helps to answer the question: can the research be applied to the “real world”? If your research is applicable to other experiments, settings, people, and times, then external validity is high. If the research cannot be replicated in other situations, external validity is low. It’s … Read more