From A for AGF Videoforschung to Z for zapping, the most important technical terms in video research are explained here.

DAP GmbH is an IT service provider in the field of market and media research, which has been commissioned by AGF to develop evaluation software for AGF data. The AGF offering of software programmes comprises AGF SCOPE, TV CONTROL, PLAN TV and AGF REACH PLANNER®.

The data rate refers to the number of bits transmitted per unit of time and is decisive for the transmission quality of TV images or video content. It is stated in megabits per second (MBit/s).

Depending on the data status, results may vary. TV data have the status "provisionally weighted" on the day following the day of broadcast. On the fourth day after the day of broadcast, the data reach the status "finally weighted" and also include usage that did not occur on the day of broadcast. If TV evaluations are not based on the status "finally weighted", this must be documented.

With the integration of streaming data on the eighth day after usage, streaming as well as convergence evaluations are possible (status: "convergent"). After the last addition of convergent content, the data reach the status "consolidated". When matching to TV programmes, streaming uses that occur 14 days before to 13 days after the broadcast of the TV programme are taken into account by default. Convergence evaluations on non-consolidated data status are to be documented.



In line with the company’s hybrid approach, streaming measurement is performed both in the census measurement and in the Desktop Panel. This data includes structural information on persons (e.g. age, sex). The census and panel measurements are aligned in the calibration process (usage level adjustment). The Desktop Panel is composed of 10,650 active panelists who allow their video-streaming usage to be measured via their private/personal PCs or notebooks/laptops.

Digital receivers are auxiliary devices or modules integrated directly with the TV set for the reception of television and digitally broadcast radio programmes. Depending on the equipment, digital receivers can also receive other digital services.

Digital television refers to the digital transmission of TV programmes. In digital transmission, conventional (analog) video and audio are converted into a binary code (0s and 1s). Unlike analog transmission, however, not every individual picture is transmitted in full, but only the part that actually changes from frame to frame. Thanks to the method of data compression (e.g. mpeg), more digital than analog programmes can be transmitted at each frequency. A digital receiver is needed to receive digital video and audio signals.

DVB-C is the standard for the transmission of digital broadcasting signals via cable.

DVB-S is the standard for the transmission of digital broadcasting signals via satellite.

DVB-T is the standard for the transmission of digital terrestrial television signals.

DSL is an acronym that stands for Digital Subscriber Line. It refers to a transmission standard under which data can be transmitted and received at high transmission rates via a bifilar copper line of the telephone network. Because DSL data is transmitted in a different frequency range than telephone data (voice or fax), users can speak on the telephone and surf the Internet at the same time. A DSL connection offers much faster Internet speeds than earlier modem and ISDN connections.

The dual-frame-method describes the telephone, randomly controlled sampling using a combination of landline and mobile phone numbers. As a result, those people who can be reached primarily or only by mobile (mobile onlys) are also included in the sample. In the case of dual frames, the sample is drawn from two frames or selection frames that completely cover the population: fixed network plus mobile. A suitable design weighting is then necessary to combine the two samples.

The duration indicates the average viewing duration of the users of a programme. It only includes the persons who actually watched TV.

DVB is an abbreviation for Digital Video Broadcasting and refers to the international transmission standard for digital television. Digital broadcast signals are transmitted via data compression (see mpeg). The addition C, S or T indicates the transmission path of the signals, i.e. cable, satellite or terrestrial. The additions S2, C2 or T2 describe the standard for high-definition television.

DVR is an abbreviation for Digital Video Recorder and describes a hard disk recorder that contains a hard disk for recording programmes.