If research particular to a field is not valid and reliable, then all the research would mean absolutely nothing.
WikiAnswers is valid when the people who answer the questions are providing valid answers. When people abuse the web site and put junk answers on the site, then it is suspect. Consider the person who...
yes, if you back that opinion up with facts.
This is
An invalid file is one where the data is bad. You need to re-export the file.