According to Amanda D. Lotz, the multi-channel transition began in the early 1980s and lasted about 20 years. Many changes happened during this transition such as the invention of the remote control, the video cassette player, and analog cable systems expanded viewer's choice and control. This era gave viewers more choice and control over what and when they wanted to view a program. Viewers were able to defy the networks' schedules, because they could record the program and watch it whenever they wanted, using the VCR and later the DVR. Producers adjusted to the government regulations and networks were forced to give up some of the control they had over program creation. Subscription channels emerged with no advertisements and the method for measuring audiences grew with the Nielsen People Meter.