Ethos corresponds to the credibility or character of the speaker. This is the reason that when a seminar is given the main speaker in usually an expert in that particular field of study. This is especially true of the sciences: math, physics, atronomy, medicine, etc... Some areas are based on percieved expertise. This might be when considering moving overseas, a person who is considered credible might be one who has lived in that particular country. Pathos speaks to the emotional connection with the audience. This can be found in an appeal to one's feelings. An advertisement for support for the homeless, comes to mind. It could also be one to Saint Jude's Medical Center, or even the local animal shelter. Each of these seek to tug on the listener's heart strings to draw them into making a commitment to help. This same method is used in writing to get the reader commited to the storyline. Logos has to do with the logical argument. Often, this is supported by statistics. As an example, "27% of all smokers will develope some form of breathing problems before the age of 60." Now, such numbers are always subject to critique but they can still be very effective in swaying the reader to the writer's point-of-view.
