NYU Prof: Google’s Click Fraud Efforts ‘Reasonable’

Barry Schwartz at the SEW blog posted yesterday about a new click-fraud report, prepared by an independent, court-appointed expert in the context of the Lane’s Gifts class action litigation. The expert is Alexander Tuzhilin, a professor of information systems at New York University. Here’s a copy of the report itself.

From the “conclusion” section:

Google has built the following four “lines of defense” against invalid clicks: pre-filtering, online filtering, automated offline detection and manual offline detection, in that order. Google deploys different detection methods in each of these stages: the rule-based and anomaly-based approaches in the pre-filtering and the filtering stages, the combination of all the three approaches in the automated offline detection stage, and the anomaly-based approach in the offline manual inspection stage. This deployment of different methods in different stages gives Google an opportunity to detect invalid clicks using alternative techniques and thus increases their chances of detecting more invalid clicks in one of these stages, preferably proactively in the early stages.

Since its establishment in the Spring and Summer of 2003 the Click Quality team has been developing an infrastructure for detecting and removing invalid clicks and implementing various methods in the four detection stages described above. Currently, they reached a consolidation phase in their efforts, when their methods work reasonably well, the invalid click detection problem is “under control,” and the Click Quality team is fine-tuning these methods. There is no hard data that can actually prove this statement. However, indirect evidence provided in this report supports this conclusion with a moderate degree of certainty. The Click Quality team also realizes that battling click fraud is an arms race, and it wants to stay “ahead of the curve” and get ready for more advanced forms of click fraud by developing the next generation of online filters.

In summary, I have been asked to evaluate Google’s invalid click detection efforts and to conclude whether these efforts are reasonable or not. Based on my evaluation, I conclude that Google’s efforts to combat click fraud are reasonable.

(My emphasis.)

The report takes a swipe at some of the other reports in the marketplace on Click Fraud (presumably the much-covered Outsell report of several weeks ago):

As a scientist, I am accustomed to seeing more direct, objective and conclusive evidence that certain methods and approaches “work.” Having said this, I fully understand the difficulties of obtaining such measures for invalid clicks by Google, as previously discussed in this report. Moreover, one can challenge most of the reports pertaining to invalid clicking rates published in the business press by questioning their methodologies and assumptions used for calculating these rates. Most of these reports would not stand hard scientific scrutiny.

(My emphasis.)

For more detail, read Danny Sullivan’s very extensive analysis of the report.


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