Verification and Validation (V\&V) is the
 process where
in
developers applies 
various tasks (usually testing) to increase the changes
 that the new 
software agrees with its specification. {\em Independent 
verification and validation} (IV\&V) is a V\&V process 
where the V\&V is performed by a group independent of the 
developer. 

The IEEE Standard for Software Verification 
and Validation~\cite{1012}  identifies three kinds of 
``independence'' necessary for  IV\&V: technical, managerial, and 
financial. 
There are many forms of IV\&V, most prevalent 
being: {\em classical, modified, internal}, and {\em embedded}. 
\bi
\item
Classical IV\&V embodies all three kinds of indepedence;
i.e. the IV\&V team reports to a different management team than the
development team.
\item
Modified IV\&V preserves technical and financial independence, 
while allowing for non-independent  managerment.
\item
Internal 
and embedded IV\&V are performed by personnel from the 
developer's organization; i.e. all three
three independence 
aspects are compromised.
\ei

According to the definition by the NASA Safety and 
Mission Quality Office, IV\&V is a ``a process whereby the 
products of the software development life cycle phases are 
independently reviewed, verified, and validated by an 
organization that is neither the developer nor the acquirer 
of the software.  IV\&V differs from V\&V only in that it is 
performed by an independent organization." ~\cite{nasa92}.

This notion, that IV\&V  is essentially the same as V\&V, needs some clarification.
An observor watching a V\&V analysts and a IV\&V analyst may see little difference
in their day to day behaviour.
They both might explore similar issues
using similar  tools and they both might record their issues in the same kind
of defect tracking tools.
Nevertheless, there are major differences. Firstly, more information is typically 
available to the V\&V team than the IV\&V team. XXXX.
Arthur et.al. observe that 
\begin{quote}
{\em the independenace  that promotes objectivity and encourages yo to consider
a wider range of solutions, which in trun can improve error detection.}
\end{quote}
In fact, an IV\&V analyst might find the same errors as V\&V analyst.



