I spoke with Robin in admissions today (btw they are great answering the phones and answering questions) and she didn't really have an answer to how to fill them out. At first she wasn't aware that it was 4 separate boxes then told me its a scroll bar but try not to have to use the scroll, which would limit it to about 10 words

I let her know that it was a very very small box if that was the case and you couldn't really write much.
Basically what we worked out was that it should fit in last year's application... which doesn't help anyone who didn't apply last year. She said it could be single or double spaced didn't matter and basically they just want you to remain on target.
For reference, last year's application had these allotted spaces for the questions they asked.
Describe research: 12 lines
Teaching Experience: 17 lines
Shadowing Question: 28 lines
Expectations Question: 28 lines
Community Service: 28 lines
Each of the longer essays comes to just over a half page single spaced with Times New Roman size 12. Hope this helps.