Thank you for providing these links! I read the two articles. The first one is the closest to what I was looking for. It contains three mostly independent expe

Thank you for providing these links! I read the two articles. The first one is the closest to what I was looking for. It contains three mostly independent experiments, comparing text, icons and web layout. Text and icon do not seem relevant to this discussion. The third part of the study compares a "traditional" website design to a new, flat one. This is more relevant to the discussion, but this comparison has three huge flaws. Firstly, according to the pictures in the article, they were comparing two specific arbitrary websites. It is not clear how this comparison can be generalized. Secondly, the study is from 2015 when flat design language was relatively new. It could measure just the difference between any "traditional" and "new" design language due to the familiarity. Thirdly, the confidence intervals are huge. I don't think there is any pair of values that are confidently separated, which would make this a null result even if the experiment itself were totally fair. The second article is very interesting, but its conclusions are non-committal. I clicked to several of the links from this article. Most of them are opinion pieces, and none that I found makes any judgement call about the comparative advantage of flat design. I'm sorry but I ignored flatisbad.com since I believe Xisbad.com can't be an unbiased source of knowledge about X and should be ignored as a matter of principle.