How is "Robot" form_factor detected?

[nejjj]

Our website currently uses WURFL (Embedded JavaScript) to show the right design of the website depending on the "form_factor" attribute returned in the globabl WURFL object and we've noticed that occasionally the following attached "User-Agents" will get detected as a "Robot" in the "form_factor" attribute even though other services don't classify these User-Agents to be "Robots". So I am curious how the "Robot" "form_factor" is detected? I have attempted to reproduce this by simply changing the "User-Agent" of my browser to one of the listings below but I was unable to reproduce the behavior so I was wondering if there was something else going on as well. Thank you for taking the time and reading this, pasted below is the list of user-agents.

- Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 AOL/11.0 AOLBUILD/11.0.1828 Safari/537.36

- Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 AOL/11.0 AOLBUILD/11.0.1828 Safari/537.36

- Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 AOL/11.0 AOLBUILD/11.0.1831 Safari/537.36

- Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/43.0.2357.130 AOL/9.8 AOLBuild/4346.2019.US Safari/537.36

- Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 AOL/11.0 AOLBUILD/11.0.1831 Safari/537.36

- Mozilla/5.0 (Windows NT 6.1; WOW64; Trident/7.0; rv:11.0) like Gecko

- Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 AOL/11.0 AOLBUILD/11.0.1805 Safari/537.36

- Mozilla/5.0 (Windows NT 10.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 AOL/11.0 AOLBUILD/11.0.1828 Safari/537.36

- Mozilla/5.0 (Windows NT 6.1; Trident/7.0; rv:11.0) like Gecko

- Mozilla/5.0 (Windows NT 10.0; WOW64; Trident/7.0; rv:11.0) like Gecko

- Mozilla/5.0 (Windows NT 10.0; WOW64; Trident/7.0; Touch; rv:11.0) like Gecko

- Mozilla/5.0 (Windows NT 6.3; WOW64; Trident/7.0; MALNJS; rv:11.0) like Gecko

[aaronp]

Hi,

After looking through the provided AOLBuild user agents, we can confirm that they are indeed bots and are properly being detected. In addition to analyzing the user agent string structure for the presence of certain keywords, we analyze the whole header request which is why you are not able to replicate the behavior you are seeing.

The other non-AOLBuild user agents are being returning false for is_robot and Desktop for form_factor, as there are nothing in the user agents to indicate they are robots.

Hope this clarifies things. Let us know if you have any other questions or concerns.

Thanks,

Aaron