Today we made "Glue Goo," an interesting blend of Borax, boiling water, food coloring, and Elmer's glue.  My corresponding teacher and I made perfect worksheets and booklets, outlining how to use our senses in conducting an experiment.  The kids would write out how they used the scientific method by: 1) Observing with their senses 2) Making a prediction 3) Drawing a conclusion.  The worksheets were so beautiful I wanted to cry.
As we began the lesson, I noticed that our beautiful worksheets were covered in colored water and sticky liquids.  But the lesson was so fascinating and messy, and the kids were learning so much, that I couldn't stop to make sure that they wrote down the answer to every single question.  After a while, I collected the worksheets and put them under the table.  Instead we talked about what the goo felt like, what it needed more of, predicted what it would do next, used words like "dissolved" and "solution," and compared the texture to other things.  We were covered in corn starch, oil, and glue.  It. Was. Awesome.
Then I realized that although we had learned so much and covered so many topics, I still had four half-blank worksheets and booklets.  My corresponding teacher came over and said, "Don't worry about it.  They were engaged and they learned more this way than they would have writing out sentences.  As long as they met all the objectives verbally, you've done your job."  It was a great reminder for me that learning does not always come the way the teacher expects it to and that lesson plans are guidelines, not rules.