GLOBAL: Most audience behaviours in most media can be captured and reported but economic and political factors frequently hamper the adoption of more accurate measurement methods, an industry figure has argued.

In a WARC Best Practice paper, Audience measurement in the digital age, Andrew Green, Global Head of Audience Solutions at Ipsos, observes that "We are in the midst of quite fundamental changes in the measurement of many media now, driven by the rapid growth in digital distribution technologies".

But, across a range of media, he suggests that a combination of vested interests and costs have hindered the speed at which audience measurement methodologies are adapting.

The "new media buying paradigm", Green explains, involves buying audiences – and having limited control over the environment where those audiences are – alongside the traditional practice of buying specific media and having a broad understanding of the editorial context.

Audience measurement practices have developed differently in each medium, however, and so have the definitions of an opportunity to see or hear an advertisement – and Green cautions that marketers should not confuse "opportunities to see" (what they are actually buying) with "exposure" (what people actually see).

Half the pixels of a digital ad being viewable for at least one second, the measure for a website ad, for example, is quite different from the newspaper and print definition of having read or looked recently at any issue of a publication (even though the ad will have run in a specific issue).

And as audiences utilise a variety of devices to access the same content, accurate measurement becomes an ever more pressing issue, but, says Green, "there are few technical barriers to measuring viewing on any device or platform".

Television measurement techniques, for example, now potentially include peoplemeters, software meters, mobile/passive meters return path data, the tagging of TV player apps, meta data from routers.

"Economics will help determine how far these initiatives are allowed to go, as well as the usual worries about changed audience data and rankings," Green concludes .

Data sourced form WARC