Check thesis abstract word limits.
Thesis abstract limits are institutional and strictly enforced at submission, commonly 300 words for a doctoral thesis and 250 for a master's dissertation. The constraint bites because an abstract must cover research aim, method, principal findings and contribution across the whole thesis — dividing the limit by your chapter count shows how little room each gets, often under 50 words. That is why thesis abstracts read so densely. Being well under the limit is also a mistake, since the abstract is what appears in repository search results and is read far more often than the thesis itself.
Headroom
Over or under = abstract words - institutional limit
Coverage budget
Words per chapter = institutional limit / number of chapters
Abstract limits, formatting requirements and submission rules are set by your institution and faculty, and vary between degree programmes and academic years. Confirm the current requirements with your graduate school or research degrees office before submitting.
Because abstracts are indexed in national and institutional repositories with fixed field lengths, and because the discipline of compression is itself part of the exercise. Three hundred words for an 80,000-word thesis forces you to identify what the contribution actually is.
Four things: the research question or aim, the method or approach, the principal findings, and the contribution to knowledge. The last is the one most often omitted and the one examiners look for — a summary of what you did is not the same as a statement of what it adds.