how to write abstract for thesis
Your style guide is another good place to look for abstract-writing tips. See, for example:
Graduate students: The required page format for the abstract in your thesis document is displayed in Appendix 8 of the End of Program Assessment Manual for Graduate Studies. The APUS Library and the APUS Center for Graduate Studies have created a 3-part video tutorial: Writing the Abstract for Your Graduate Capstone Thesis at AMU/APU.