Does the dissertation writer know in advance who is likely to be on the committee? In that case, it would be a matter of knowing clues of their individual opinions as it would relate to your topic and bending the wording carefully and adding or deleting data to impress or keeping certain members content that their own works are not threatened while struggling to keep intellectually honest. I learned early on to know the biography of my professors and make notes in the margins as to their favorite topics and colored opinions. Fortunately, 80% of the time I was in agreement.
Here's a long answer, please feel free to skip/ignore if not interested!
Thanks for asking, Dyna!
Ah, it was a hornet's nest tbh. Knowing their bios didn't help, it was a revolving door for my committee members. I had no control over 4 of the 5 professors on the committee, and the one I was able to request bailed out at the last minute and was replaced by someone who had less than no knowledge on my topic but came from an associated department. As my topic was on the edge of the usual for my department, the four other faculty members were in disagreement with each other as to whether they even liked the topic or not. I found this out at my actual defense, not fun.
My first advisor who strongly encouraged me and approved the topic was the head of the department and brilliant. She worked with me for just under a year and then suddenly took a year-long sabbatical. My second advisor was not an expert in my area but knew me well and liked me. He had me re-cast and rewrite about 1/2 or a bit more of what I had already finished to suit his take on things. He took ill towards the end of that year and suddenly took a year-long sabbatical. My third advisor didn't know me well, wasn't really deeply informed about my area, but was supportive and got very involved with my work. She had me totally re-cast and rewrite over 1/2 of what I had already finished and rewritten to more closely reflect her take.
I prefer not to say the topic or area, but it is one where there are some hard facts and some theories and some evidence, and some inconclusive but sound speculations, which allowed for advisors to have different perspectives on the same material. I found out that getting approved was as much about making my material suit the advisor's views as my own, thus the intense politics.
The only way I got through it was to go and privately hire a professor of academic writing at another major university (a competitor to my university) who coached me in insane detail, line by line, in weekly sessions on how to write my dissertation so it would get through. Mind you, this is not necessarily about clear and informative writing, it's about being academic enough to be "official."
The dissertation defense, a two-hour oral defense and grilling by the five faculty members, went mostly ok, with them spending a good chunk of time arguing with each other over their differing philosophical perspectives on things. They seemed to deal with
my answers to their challenges to my work fairly well, until faculty member #5, the last minute fill-in, started trashing my topic entirely, and gave me a very hard time based on his ignorance and biased opinions. Mostly he chastised me for not agreeing with him, didn't really ask me much about how I could explain or justify my work.
Finally my advisor stepped in and said she had heard enough and we should conclude. I think in their private voting discussion she squashed most of his objections pretty well. It had to be a unanimous vote, but he demanded such major and inaccurate changes and revisions to my text in order to approve it that, with my advisors, approval, I had to go to the Dean and plead my case. The Dean spent about 15 minutes listening to me, read my advisor's letter, thumbed through my dissertation (about 300 pages iirc.), looked at the list of demands the non-topic faculty member was insisting on, looked at me and said "Do not ever repeat this or I will deny it, but he is an idiot..." and approved the dissertation on the spot.
And that was how I finally graduated with all the hair on my head still intact... but barely. <g>
Whew!
[edited to add a phrase in bold for clarity]
