Icebergs are often used as metaphors for describing people: we only see what’s presented to the world, but there can be so much more going on beneath the surface.
We see a person, but don’t see their history, their feelings, their thoughts, their worries, their problems and so much more. Sometimes not knowing these things can lead to problems if we make incorrect assumptions about what we see.
The iceberg metaphor – things unseen beneath the surface – stretches neatly to reflect on a PhD thesis too.
When a thesis is submitted it’s a finished work. Examiners or anyone who reads it can read it, hopefully understand and consider what it means. Depending on their knowledge they might be able to ask questions or make assumptions about how something happened or why something was arranged in the way it was.
But they can’t know it all. They can’t see beneath the surface and know the last three (or four or seven) years of research.
They need you for that.
Having done the work you do see beneath the surface of your thesis iceberg. You see the mass of work and knowledge that is under the bright surface of new understanding. You can share that with your examiners in your viva and show them what they need to know for their own understanding.