ie/objects/linstone-perspectives.html
see Linstone 1981 and Linstone 1984
T - technology
P - personal
O - organizational
short horizon = high discount, long horizon=low discount
personal is the shortest
social
technology time can have long time horizons because of the longevity of what is "built"
T - technical report
O - technical reports plus others such as interviews, scenarios
P - scenarios, summaries, private discussions