null
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null
(nul)1. insignificant; having no consequence or value.
2. absent or nonexistent.
3. zero; nothing.
null
Molecular biologySee Null mutation.
Statistics
Completely absent; a set with no members or of zero magnitude. If a field has a value of null, it means that the value is unknown. A null value is not the same as a value of zero, and the difference can be crucial. For example, when calculating the average value of a field among many records where one row contains a zero, the zero gets factored into the average; if the field has a null value, it does not get factored in to the average.
null
an absence of information, as contrasted with zero or blank or nil, about a value.
null cell
called also null lymphocyte; see null cell.
null hypothesis
a statistical hypothesis which states that one variable has no association with another variable, or set of variables. That is, the observed results can be explained by chance alone.
null lymphocyte
see null cell.