What to do if you have a problem: errors, bugs, corrections
Everyone that uses computers experiences difficulties
from time to time. Sometimes, it is because the software they are using
really does contain an error or fault (a "bug"), so that it does not work
in the way it was supposed to. But very often, there is nothing wrong with
the software: the cause of the trouble is how it is being used, or how
it was installed. In both cases, human error plays a large part:
Although I will acknowledge and attempt to rectify my mistakes,
I do not offer any kind of bespoke (i.e. individual, one-to-one) service
for fixing problems with the software. Nor (as explained in the textbook
and on the companion CD-ROM) do I or Cambridge University Press provide
any kind of warranty regarding my software (see our warranty
it may be my mistake (as far as programs I have written are
concerned, or my explanation of how to install and use the software may
be in error)
it may be your mistake (you might not have followed the correct
it may be miscommunication: perhaps I have not explained
things in a manner you understand.
Nevertheless, when an error or bug is my fault, I will
take reasonable steps to fix it and provide a "bug fix" - an explanation
of how to recognise and rectify the problem - on this website. "Reasonable"
means that I will devote as much time to solving the problem as I can,
taking account of the fact that I have a full time job working for the
University of Oxford, and that work on this textbook and course materials
is essentially a spare-time activity.
Here is the recipe for fixing a bug, then:
First, let's establish that it really is a bug. Check
that you have followed the instructions in the textbook exactly.
Common causes of problems include: users typing capital letters where small
letters are needed, or vice-versa; punctuation confusions, such as incorrect
spaces, the wrong quote symbol (e.g. ` instead of '), - (hyphen) instead
of _ (underline) etc.
Similarly, check that the text of the program you are using
is correct. For example, if you have edited a copy of one of my programs,
perhaps that editing has introduced a mistake. You can check this by copying
the original file from the CD-ROM.
If the previous two steps don't solve the problem, it could
be that your computer or operating system is not working properly. The
simplest check to make in this case is to reboot (i.e. shut down and re-start)
If you get to this step, it is beginning to appear more likely
that there is a fault in the software. Please click on this
link to a list of previously reported problems and how to deal with them,
and see if the problem you have experienced is among them, and what to
This page last edited on 6/1/04.