Instead, it issued statements alluding to it.

"Engagement occurs as a result of a brand idea or media the consumer experiences which leaves a positive brand impression. It is now a critical advertising model to replace GRPs in the 21st century," Dr. Joseph Plummer, chief research officer for the ARF, said in the statement, adding: "It is important that we think hard about engagement to develop a robust measurement of when consumers are strongly engaged in brands, brand ideas and their surrounding environments."

In February, during a Newspaper Association of America marketing conference presentation, Plummer released what he described as the MI4 task force's working definition: "Engagement is turning on a prospect to a brand idea enhanced by the surrounding media context."

On Monday, the ARF indicated that is still the focus, noting that the "definition of engagement aims to make an improved ability to measure the concept of when a consumers mind is 'turned on' to a brand idea."

That appears to leave much room for interpretation of what engagement might mean specifically for media planning and buying. That may become clearer this morning, during the opening session of the second day of the ARF's conference, which focuses on the topic of engagement.

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