Time shift viewing
At the start of the 2010 ratings year, OzTAM introduced its Time Shift Viewing service in response to the increasing presence of personal video recorders (PVRs) in Australian households.
It was the most significant change to Australian television audience measurement since people meters were introduced in 1991.
OzTAM's Time Shift Viewing service captures viewing of television broadcast programming played back at normal speed through the TV set within 28 days of the original broadcast.
This can include pausing a program as it is broadcast live and then continuing to watch it in playback mode (‘As Live’) on the same research day (i.e., before 2am), or playing back a program on another day through the TV set within seven days of the original broadcast (‘Time Shift to 7’). From April 2016, OzTAM also offers 8-28 Day Time Shift Viewing in its television ratings database.
To capture Time Shift Viewing, OzTAM and its ratings service provider Nielsen TAM have deployed a sophisticated metering system called Unitam.
Unitam uses state-of-the-art content matching technologies to measure all viewing to all television channels on all TV sets in OzTAM panel homes, both in the Metropolitan Total TV and National STV services.
To ensure that As Live and Time Shift viewing is incorporated in OzTAM ratings, reference centres across Australia store all the broadcast content for every channel in their respective area for 28 days after broadcast. They identify whether the programming viewed on TV sets in panel homes matches content that was broadcast earlier in that 28-day period. Content matching means Unitam looks for the same programs, promotions and advertisements.
Only broadcast minutes played back at standard (normal) speed are included in OzTAM viewing figures; fast-forwarded minutes are not counted. This means, for example, that if a panel home plays back 25 minutes of a 30-minute program in standard speed, only those 25 minutes will be included in OzTAM viewing figures. OzTAM ratings do not include material that has been recorded but not actually viewed (played back).
OzTAM delivers three data sets each day:
For example, on Monday morning OzTAM supplies Overnight ratings for yesterday (Sunday) and Consolidated 7 ratings for programs that aired the previous Sunday (8 days earlier). Consolidated 28 ratings are available in the elemental database for programs that aired on the Sunday four weeks earlier (29 days earlier).
- Overnight – delivered each morning. Includes ratings based on Preliminary Times for yesterday's programs that were watched as they actually went to air ('Live') or were recorded and played back by 2am ('As Live').
- Consolidated 7 – delivered each morning (at the same time as Overnight data) for the corresponding research day a week (8 days) earlier. Consolidated 7 data takes account of Confirmed Times as well as ‘Live’, ‘As Live’ and ’Time Shift to 7’ viewing.
- Consolidated 28 – available each morning in the elemental ratings database (at the same time as Overnight and Consolidated 7 data) for the corresponding research day four weeks (29 days) earlier. Consolidated 28 data takes account of Confirmed Times as well as ‘Live’, ‘As Live’ and 'Time Shift to 28' viewing.
Refer to OzTAM’s Data Availability Calendar for more information.
See also Time Shift Viewing reporting variables.
For using Time Shift to 28 days data please see the guidelines