Public speaking is a learned skill. It takes practice. Part of it is getting over the fear of public speaking and the other crucial aspect is refining how to speak in public. I was fortunate enough to have a Toastmasters group at my last job. We were an informal club, but followed the Toastmasters International guidelines. Part of process is having a Ah-Counter tally the "fillers": the um's, uh's, and ya know's. Had I not participated in this group, I never would have known how many times I used a filler in even a three-minute talk (after you go past 10, the counter stops counting). It gave me a keen awareness of how fillers weakened my speeches and arguments. Now, I take my time when public speaking and rather than say a filler, I talk more slowly and pause to gather my thoughts.
I decided to count the fillers of my colleagues, just out of curiosity, to see how many times they used fillers. Turns out, they use a lot. In one 20-minute presentation, there were 72 ums. That's about an um every 16 seconds. I counted 58 ums in a 15-minute presentation (an um every 15 seconds) and a combined 28 ums and ya knows for a 15-minute presentation (an um every 30 seconds). I hate to see my brilliant and creative classmates sabotage their hard work due to lackluster presentation skills, but because I do not want to be the asshole who points it out to them, I will just... um... blog about it instead, ya know?