JJ, as I recall, Elder advocates the use of multiple time frames, but I don't think that his "triple screen" concept necessarily requires it. If memory serves, markets are screened first with a trend indicator, then with an oscilator reading going against the trend, and finally with price moving in the trade direction (or his own "Force Index" if memory serves). Each of these screenings can be performed using the same time frame. I very much like the concept, but without the indicators.