Based on the combination of duration and scope, different types of trend can be outlined. ‘Hype’ is when the scope of effects increases in a very short time, followed by an equally fast decrease. In comparison, a ‘niche trend’ has changes that do not reach a certain threshold or advance beyond a defined range of scope. These can have varying intensity and continue for an extended period. ‘Real’ trends, however, achieve the trend threshold after a period of about five years and usually decline after a further two to three years.