24.6 > Explain why program inspections are an effective technique for discovering errors in a program. What types of error are unlikely to be discovered through inspections?
Program inspections ensure that fresh eyes read over code that could have defects in it. Sometimes it is hard to find errors in your own code if you have spent hours and hours writing it - it really helps to get a second opinion, especially if it is in the context of a program inspection, where the team members know what the code needs to do and there is a moderator who can ensure that criticism is appropriate and unbiased. When programming for a team, it is fair that the team will get to review each others code before the code is put to use - this enables everyone to be a part of the work, and everyone is culpable for any failures.
I think errors that are unlikely to be discovered through inspections would not be in the functionality of the code itself, but maybe in how that component works with others when the program as a whole is run. This is hard to check until the team's release of the code has been combined with other working parts of the software. But ensuring that the code works as expected in a small capacity will go a long way in getting it to work effectively with the software as a whole.