  We present CWRCzech, Click Web Ranking dataset for Czech, a 100M
query-document Czech click dataset for relevance ranking with user behavior
data collected from search engine logs of Seznam$.$cz. To the best of our
knowledge, CWRCzech is the largest click dataset with raw text published so
far. It provides document positions in the search results as well as
information about user behavior: 27.6M clicked documents and 10.8M dwell times.
In addition, we also publish a manually annotated Czech test for the relevance
task, containing nearly 50k query-document pairs, each annotated by at least 2
annotators. Finally, we analyze how the user behavior data improve relevance
ranking and show that models trained on data automatically harnessed at
sufficient scale can surpass the performance of models trained on human
annotated data. CWRCzech is published under an academic non-commercial license
and is available to the research community at
https://github.com/seznam/CWRCzech.
