Methods and apparatus for detecting a composition of an audience of an information presenting device are disclosed. A disclosed example method includes: capturing at least one image of the audience; determining a number of people within the at least one image; prompting the audience to identify its members if a change in the number of people is detected based on the number of people determined to be within the at least one image; and if a number of members identified by the audience is different from the determined number of people after a predetermined number of prompts of the audience, adjusting a value to avoid excessive prompting of the audience.