When Sketches are Better for Communicating Ideas

I ran across a blog post on Linkedin by Nancy Duarte that explores why it is sometimes better to present ideas in a rough, sketchy form than it is to present them in a polished form.  I’ve found this to be the case in my work, especially on projects where public and/or owner input is crucial in the early stages.  Presenting ideas with sketches or in a less polished form tends to convey the message that the ideas are open to discussion and revision, providing a better opportunity for meaningful feedback.  What do you think?  Does the level of “polish” in a presentation affect how you provide feedback?  Read the article and let us know in the comments.