Your ability to speak publicly is important in careers like management, teaching, coaching, training and marketing. To command attention and respect, you must establish credibility. Preparation before a speech and techniques used during the presentation help you build credibility.

Knowledge and Preparation

You can't establish credibility during a presentation if you haven't taken the steps to earn it. One key to effective speeches is a firm understanding of the topic. Education and training give professionals a foundation of expertise. Research, an outline and materials preparation set the stage for communication success. As you prepare a presentation, consider the visual appeal of PowerPoint and other technology applications. Organize your presentation in a way that makes sense to you and the audience. Practice. Comfort with the structure and content of your material gives you confidence. Having a well-prepared bio for the person who introduces you to the audience also aids in selling your accomplishments and expertise.

Set a Positive Tone

First impressions have a major effect on the audience's perception of your credibility. In some cases, speakers promote presentations, classes, training sessions or meetings with brochures or handouts. At large conferences, a program with speaker bios is often distributed. In these materials, you have a chance to share your education and professional background. When you begin your speech, include relevant background that the audience will view as proof of expertise. A teacher or professor meeting a class on the first day might share background on degrees, professional experience and years teaching. An author of a book typically references the book.

Use Your Nonverbals

In face-to-face communication, your body language and tone of voice have major impact on the message. Use these factors to project a professional presence and command attention. As you talk, stand with a firm but relaxed posture, make eye contact with audience members, show a warm smile, use natural hand gestures and talk with pacing, volume and emphasis. When you have confidence in your expertise and display it comfortably through effective nonverbal mannerisms, it's easier for your audience to accept your experience as a given.

Speak with Accuracy and Offer Support

Over the course of your presentation, you gain and maintain credibility by conveying accurate information and backing it up. Don't state opinions as facts or misstate important points without knowing your message is accurate. You may have knowledgeable audience members who quickly realize something is off. One of the most effective ways to show you have credibility is to back up your own cohesive thoughts with supporting charts, graphs, quotes or data. After making a point on leadership, share a related quote from a recognized leader. When making compelling points on a topic, show a recent chart or graph from a study that reinforces your statements. A handout with your book list or website link allows audience members to further explore your credentials after the presentation.