Analysis is invalid

Invalid Recipes

In complex fluids the Gaussian Diffusion Approximation is generally invalid.

The Gaussian Diffusion Approximation proposes that the distribution of displacements Δx for a particle diffusing through a complex fluid has a Gaussian dependence on Δx. We demonstrate from experimental evidence and computer simulations that this approximation is generally incorrect in complex fluids. As a result, experimental studies that have used the Gaussian Diffusion Approximation to inter...

Invalid measurement validity.

Concurrence looks at how a measure relates to a gold standard. If, as frequently occurs, there isn’t one, the next best is the correlation with other established measures. This assumes that the latter are themselves valid, which may not be true, and risks stifling innovation, a source of concern if a paper is criticized on this ground. More straightforwardly, concurrence also means that a test ...

On Phase II SPC in Cases When Normality is Invalid

Conventional statistical process control (SPC) charts require the normality assumption on the process response distribution. In reality, this assumption is often invalid. In such cases, it has been well demonstrated in the literature that results from control charts using the normality assumption may not be reliable in the sense that their actual false alarm rates could be substantially larger ...

Representing "Just Invalid" Knowledge

Data, information and knowledge are all represented in a single formalism as “items”. Items contain two types of acceptability measures that measure the invalidity of item instances. Objects are item building operators that also contain two types of acceptability measures. These acceptability measures define a graduated acceptability region for data, information and knowledge. This region repre...