Nondifferential measurement error : Nondifferential measurement error refers to errors in data collection that do not vary by the level of the variable being measured. In other words, all participants in a study are equally likely to experience this type of error. This is in contrast to differential measurement error, which occurs when the error […]

Noncentral distributions : A noncentral distribution is a statistical distribution that is not centered around its mean value. This means that the distribution has a nonzero mean value, but the values of the distribution are not evenly distributed around that mean value. Instead, the values may be skewed or asymmetrical, with a higher concentration of […]

Nomogram : A nomogram is a graphical tool that allows for the rapid calculation of a specific value based on a set of input variables. It is often used in fields such as engineering, medicine, and finance to quickly solve complex equations or make predictions based on specific data. One example of a nomogram is […]

Nominal Variable : A nominal variable is a type of categorical variable that assigns categories or labels to observations, but does not have any inherent order or ranking. This means that the categories cannot be meaningfully compared or placed on a scale. For example, consider a study that wants to classify individuals based on their […]

Nominal significance level : The nominal significance level, also known as the alpha level, is a measure of the probability of making a Type I error in statistical analysis. A Type I error occurs when a statistical test rejects the null hypothesis, when in fact it is true. The nominal significance level is the probability […]

Noise : Noise in data refers to random variations or errors in the measurements or observations that are made. These random variations can arise from a variety of sources, such as measurement errors, background noise, or interference from other sources. Noise can have a significant impact on the accuracy and reliability of data, and it […]

No free lunch theorem : The no free lunch theorem states that no algorithm or approach can perform optimally on all possible problems. This means that there is no one-size-fits-all solution that will work best for every situation. Essentially, the theorem suggests that there are trade-offs and limitations to every decision or approach. To understand […]

N of 1 clinical trial : A N of 1 clinical trial, also known as a single case study or individualized clinical trial, is a type of clinical trial that focuses on the effects of a specific treatment on an individual patient. This type of trial is conducted on a single patient, rather than a […]

Newton–Raphson method : The Newton-Raphson method is a widely used iterative method to find the roots of a given equation. It is based on the idea that if we can approximate the root of a given equation, we can use that approximation to find an even better approximation. The first step in the Newton-Raphson method […]

Newman-Keuls test : The Newman-Keuls test is a statistical procedure used to determine significant differences between means in a one-way or two-way analysis of variance (ANOVA). It is a post-hoc test, meaning it is used to make comparisons after the initial ANOVA has been conducted. One example of the Newman-Keuls test might be to compare […]