Cross-device tracking is used to capture consumer engagement across smartphones, tablets and desktop computers. 

Using its Digital Ad Ratings, Nielsen will conduct measurement of the accuracy of cross-device graph providers, with a view to providing greater rigour in methodological approach and scale. The methodology will evaluate providers across five metrics: match rate, precision, recall, cross-device scale and a composite score. 

"The growth of cross-device providers underscores market demand to understand consumer behaviour across the various devices we use and engage with everyday," said Thomas Eaton, senior vice president of digital at Nielsen.

"Nielsen’s cross-device verification will bring greater rigour and transparency to the measurement of cross-device graphs and provide the market with valuable insights to assist in more informed buying and selling decisions."