During presentations or lectures, I try to always use a back channel. Sometimes there is a lot of information to cover - and I can't get to everyone's questions. Different tools allow you to do different things with students or an audience. When I think of my classroom I really like back channels that give my shy students a place to ask questions or contribute to a conversation, the chance for everyone to ask questions (there's always that one with a million questions..in a back channel they won't complete dominate the discussion), an opportunity to get a sense of students' interest about a topic, and most importantly branch the conversation outside of the classroom. So, below are three tools I use with students and teachers:
Today's Meet This is a free service to host a back channel during lecture, discussions, or presentations. I've used Today's Meet in a couple different scenarios: first class of the year, professional development presentations, conference presentations, and edCamps. When I introduce a unit, I like using back channels. Students can write questions or comments as they pop into their heads. A back channel enables students to ask more questions or add comments. It's a less stressful environment, in my opinion. Plus, a lot of times I have to stop to answer a question, or hold a question, get to the student, and they have forgot the question.
Socrative Informal assessment meet back channel! Socrative allows student to reply to questions without entering their names - so you can get anonymous feedback. In a single response activity, I ask a question and students respond on Socrative. Great way to check for understanding. Socrative also has quiz-based activities that give students short quizzes - multiple choice, true/false, and short answer. Recently they added the option to include pictures in the questions - great for the math people! The results show up in real-time and you can download a report of all students' answers when the quiz is completed.
Padlet KWL charts are great - and I"m still a fan of writing on my white board...but I also like putting the responsibility of what they know, what to know, and what they've learned on them. So, using Padlet is a great way to accomplish this. Padlet, formerly known as Wall Wisher, is a great blank space. You can randomize the posts or customize it like a news feed. I've even used it as a mock Twitter feed when students work on simplified summaries. You can save your padlets and download as a pdf.