Definitions of unsettled on the Web: still in doubt; an unsettled issue; an unsettled state of mind. changeable: subject to change; a changeable climate; the weather is uncertain; unsettled weather with rain and hail and sunshine coming one right after the other. wordnet.princeton.edu/perl/webwn.
Credit and criminal history checks will be conducted on all applicants. For a Top Secret security clearance, the background investigation includes additional record checks which can verify citizenship for the applicant and family members, verification of birth, education, employment history, and military history.
Generally polygraph exams are not used when only a collateral security clearance is needed. The Office of Personnel Management, which conducts 90% of all federal background investigations, does not conduct polygraph exams.