Genome-wide significance 1970-01-01
Genome-wide significance refers to a statistical threshold used in genome-wide association studies (GWAS) to determine whether a particular association between a genetic variant and a trait (such as a disease) is strong enough to be considered reliable and not due to chance. Given the vast number of genetic variants tested in GWAS—often millions—there's a high risk of false positives due to random chance. To address this, researchers apply a stringent significance threshold.
Genomic control 1970-01-01
Genomic control, often referred to as genomic selection or genomic prediction, is a method used in genetics and genomics to improve the accuracy of breeding programs. It is primarily applied in agriculture, animal breeding, and plant breeding to enhance desired traits in organisms, such as yield, disease resistance, or environmental adaptability. The concept involves using genome-wide information, typically derived from high-throughput genotyping technologies, to identify genetic markers associated with specific traits.
Inclusive composite interval mapping 1970-01-01
Luria–Delbrück experiment 1970-01-01
The Luria–Delbrück experiment, conducted by Salvador Luria and Max Delbrück in the 1940s, was a pivotal study in the field of microbial genetics that provided important insights into the mechanics of mutation. The experiment aimed to address the question of whether mutations in bacteria occur as a response to environmental pressures (adaptive mutations) or whether they arise randomly, independent of the selection pressure (spontaneous mutations).
Multispecies coalescent process 1970-01-01
The Multispecies Coalescent (MSC) process is a theoretical framework used in population genetics and phylogenetics to model the ancestry of species and the gene flow between them. It extends the coalescent theory, which was originally developed to describe the genealogical processes of a single population, to multiple species that may have shared a common ancestral population.
Nested association mapping 1970-01-01
Nested association mapping (NAM) is a genetic mapping strategy used primarily in plant breeding and genetics research to identify and exploit quantitative trait loci (QTL) associated with specific traits of interest. The key feature of NAM is that it allows researchers to understand the genetic architecture of complex traits by leveraging a diverse set of recombinant inbred lines (RILs) derived from multiple parental lines.
Brownian dynamics 1970-01-01
Brownian dynamics is a simulation method used to study the motion of particles suspended in a fluid. It is based on the principles of Brownian motion, which describes the random movement of particles due to collisions with surrounding molecules in a fluid. This technique is particularly useful in analyzing systems at the microscopic scale, such as polymers, nanoparticles, and biomolecules.
Brownian motion 1970-01-01
Brownian motion, also known as particle theory, is the random movement of small particles suspended in a fluid (like air or water) resulting from their collision with the fast-moving molecules of the fluid. This phenomenon was named after the botanist Robert Brown, who observed it in 1827 while studying pollen grains in water. The key characteristics of Brownian motion are: 1. **Randomness**: The movement is erratic and unpredictable.
Substitution model 1970-01-01
The substitution model is a theoretical framework used in various fields, including economics, linguistics, and biology, to analyze how one entity can replace another. Here are three common applications of the substitution model: 1. **Economics**: In economics, the substitution model often refers to consumer behavior regarding the substitution of one good for another. For instance, if the price of coffee increases, consumers might substitute it with tea.
W-test 1970-01-01
The "W-test" can refer to different concepts depending on the context, as there are several tests in statistics and other fields that might use similar nomenclature. Here are a couple of possibilities: 1. **W-test in Statistics**: This could refer to the **Wilcoxon signed-rank test**, which is often denoted as "W". This non-parametric test is used to compare two paired groups to assess whether their population mean ranks differ.
Bayesian inference 1970-01-01
Bayesian inference is a statistical method that applies Bayes' theorem to update the probability of a hypothesis based on new evidence or data. It is grounded in the principles of Bayesian statistics, which interpret probability as a measure of belief or certainty rather than a frequency of occurrence. ### Key Components: 1. **Prior Probability (Prior):** This is the initial belief about a hypothesis before observing any data. It reflects the information or assumptions we have prior to the analysis.
Statistical forecasting 1970-01-01
Statistical forecasting is a method that uses historical data and statistical theories to predict future values or trends. It employs various statistical techniques and models to analyze past data patterns, relationships, and trends to make informed predictions. The core idea is to identify and quantify the relationships between different variables, typically focusing on time series data, which involves observations collected at regular intervals over time.
Empirical characteristic function 1970-01-01
The empirical characteristic function (ECF) is a statistical tool used in the analysis of random variables and processes. It is a nonparametric estimator of the characteristic function of a distribution based on a sample of observations. The characteristic function itself is a complex-valued function that provides useful information about a probability distribution, such as the moments and the behavior of sums of random variables.
Fiducial inference 1970-01-01
Fiducial inference is a statistical framework developed by the mathematician Ronald A. Fisher in the early 20th century. It is intended for making inferences about parameters of a statistical model based on observed data without relying on the subjective probabilities associated with prior distributions, which are common in Bayesian statistics.
Frequentist inference 1970-01-01
Frequentist inference is a framework for statistical analysis that relies on the concept of long-run frequencies of events to draw conclusions about populations based on sample data. In this approach, probability is interpreted as the limit of the relative frequency of an event occurring in a large number of trials. Here are some key characteristics and concepts associated with frequentist inference: 1. **Parameter Estimation**: Frequentist methods often involve estimating parameters (such as means or proportions) of a population from sample data.
Informal inferential reasoning 1970-01-01
Informal inferential reasoning refers to the process of drawing conclusions or making inferences based on observations and experiences without employing formal statistical methods or rigorous logical arguments. This type of reasoning relies on informal logic, personal judgments, and anecdotal evidence rather than structured data analysis or established scientific principles. Key characteristics of informal inferential reasoning include: 1. **Contextual Understanding**: It takes into account the context in which observations are made.
Randomised decision rule 1970-01-01
A randomised decision rule (also known as a randomized algorithm) is a decision-making framework or mathematical approach that incorporates randomness into its process. It involves making decisions based on probabilistic methods rather than deterministic ones. This can add flexibility, enhance performance, or help manage uncertainty in various contexts. **Key Characteristics of Randomised Decision Rules:** 1. **Randomness:** The decision rule involves an element of randomness where the outcome is not solely determined by the input data.
Resampling (statistics) 1970-01-01
Resampling in statistics refers to a collection of methods for repeatedly drawing samples from observed data or a statistical model. The main purpose of resampling techniques is to estimate the distribution of a statistic and to validate models or hypotheses when traditional parametric assumptions may not hold. Resampling is particularly useful in situations where the sample size is small or the underlying distribution is unknown.
Sampling distribution 1970-01-01
A sampling distribution is a probability distribution of a statistic (such as the sample mean, sample proportion, or sample variance) obtained from a large number of samples drawn from a specific population. In essence, it shows how a statistic would vary from sample to sample if you were to take repeated samples from the same population.
Transferable belief model 1970-01-01
The Transferable Belief Model (TBM) is a theory in the field of evidence theory, particularly dealing with the representation and management of uncertain information. It was introduced by Philippe Smets in the context of artificial intelligence and decision-making. ### Overview of the Transferable Belief Model: 1. **Foundation on Belief Functions**: The TBM is based on belief functions, which provide a framework for managing uncertainty.