Search strategy errors will affect the validity of a review. Check your searches have retrieved papers that you would expect to find. For example, if a relevant and high-quality paper has been retrieved during the initial scoping stage using Google Scholar but not by your database searches, you should investigate the reasons why and adapt your search strategy accordingly.
It is best practice to have someone evaluate your search. This could be another member of the review team or, where possible, a librarian or information specialist. GCU Library is currently unable to offer this service. There are guidelines available to help with peer review of electronic search strategies. Although these were originally developed for expert searchers, such as librarians, they can also be used by students and researchers.