If you do not want resources to show in search results for low level or general users you can do a few different things...You'll have to decide yourself which method works best for your situation:
Contributor config setting (defaults shown):
# Should a user that has contributed a resource always have open access to it?
$open_access_for_contributor=false;
# Should the resources that are in the archive state "User Contributed - Pending Review" (-1) be
# visible in the main searches (as with resources in the active state)?
# The resources will not be downloadable, except to the contributer and those with edit capability to the resource.
$pending_review_visible_to_all=false;
# Should the resources that are in the archive state "User Contributed - Pending submission" (-2) be
# searchable (otherwise users can search only for their own resources pending submission
$pending_submission_searchable_to_all=false;