Manual testers working in an agile environment are often encouraged to follow the same working practices as those working in a waterfall environment. This approach frequently leads to a manual testing effort that takes too long to prepare, execute and maintain. The result is often anything but agile.
At the other end of the spectrum, manual testers working in an agile environment are encouraged to simply browse the software looking for bugs that the team’s automated tests did not detect. Whilst this approach is more in keeping with the brisk nature of agile projects, it often fails to find important bugs.