The word “might” should never appear in your thesis. Be direct and clear about the point you want to make, and don’t hedge or soften your statement. If you don’t feel strongly enough about your argument to put it in a declarative sentence, you should choose another paper topic. Aim for strong language that makes your support for your thesis entirely clear. Whether you’re establishing cause and effect, advocating for a solution, or interpreting something, you need to be your argument’s number one fan, and that relies on you using clear and definitive language.
The thesis abstract or summary is what will be read first, to give an indication of the parameters of the study, its depth and breadth, its context and the scholarly contribution it makes. It may be the basis on which a prospective examiner agrees (or not!) to examine your thesis. It is important that it is written in a concise and focussed manner so that it identifies the salient features of the research, the problem or research question, the approach adopted, and its findings. In general the thesis abstract is about 300 words, and for Monash doctoral theses, no more than 500. (Check the norm in your discipline.)