When you are evaluating your material for an informative speech you should be particularly careful to make sure the material is not?

Make sure the material is not prejudiced or insulting; make sure it is not biased; make sure it is not out-dated or no longer accurate; and make sure it is not so far over people's heads that they won't be able to understand it. Rule number one in public speaking is "know your audience," so find out what kind of people will be listening to you: their age groups, ethnicities, level of education, etc. The more you know about the audience, the better able you will be to adapt your speech so that they will relate to it and find it accessible, whether they agree with you or not.

When giving an informative speech, choose factual material (don't make claims that cannot be proved; don't exaggerate or manipulate the information). Be personably and friendly in your delivery-- professionalism is important, but don't just read from your notes; always present the information in an interesting way, by making eye contact with your audience, as well as by using visuals when possible (photos, easy-to-read charts, even a short segment of a video). Be sure to use up-to-date information (you can refer back to the past, but make sure you are giving people the latest studies or the most recent discoveries). And be sure your speech is not so filled with jargon and/or slang that the average listener won't be able to follow it. Your job is to INFORM, so choose material that will leave the audience feeling they learned something useful.