"undercover methods" is a correct and usable phrase in written English.
It refers to ways of gathering information or conducting investigations while pretending to be someone else or concealing one's true identity. Example: The detective used various undercover methods to gather evidence against the suspect, including infiltrating his inner circle and posing as a potential buyer.
A spokesman said: "'This was an investigation into a matter of considerable public interest and the newspaper believed that use of undercover methods was justified.
But the EIA, which uses undercover methods to probe the trade, says things are not as good as they seem; in 2007 its researchers found a roomful of illegal ivory, including an uncut tusk, for sale in the city of Dalian.
However, it is hypocritical for lefties to decry such undercover methods when it is a standard left-wing tactic to use these very same methods - rightfully I might add - to expose bigoted comments by conservative lawmakers, intrusive government surveillance, or various other forms of conservative malfeasance.
This observation suggests that the Bayesian methods may undercover when the point estimate of the ICC b is small.
Shi et al. observed that for the high number of taxa, although the number of trees included in the GLS confidence set increased, the method undercovered.
Chris Atkins, a filmmaker based in London, decided to turn the tables, going undercover to document dubious reporting methods in the tabloids' pursuit of celebrity scoops.
Going in undercover is often the best method, but, as Ormsby says, "To get access to the most extreme sites, members have to provide original material depicting child abuse, so obviously law enforcement can't participate in that".
It also judges that the methods used by some undercover officers at times clearly involved "the violation of other individuals' human rights, and appear also to have extended to deceiving courts".
American intelligence agencies will argue that some of the information they possess cannot be disclosed without compromising undercover agents and collection methods.
The prosecutor said Albert Ermmarino left it up to the hit man -- actually an undercover detective -- to determine the method of murder.
The Fish and Wildlife agents called their undercover efforts Operation Malossol, for the method of preserving caviar by lightly salting it, and Operation Wedgehead, for the nickname of the American paddlefish.
