Should the introduction of a thesis have figures/pictures? I'm writing my master thesis in network formation theory. I believe that a picture with network nodes in the introduction will help the readers understand what my model is and what I am trying to prove. I doubt most readers would read past the introduction anyway so if they do not understand the introduction then that would be a big problem for me.
Is that advisable or not? What if I am using the introduction as the writing sample for my PhD application?
I can't think of any reason in general that you should not do this if it makes sense in the context of the paper. If you can express the underlying concept better with a figure then it is better than to use words.
But an advisor might disagree, in the context of this paper. And an editor or reviewer of the paper might disagree. In that case, change it.
But the paper is yours. Do what you thing makes the most sense and makes the paper accessible to your audience.