One of my pet peeves is that these articles never report the a priori distribution of labels that are being predicted. Guessing whether you're at sitting vs wal

One of my pet peeves is that these articles never report the a priori distribution of labels that are being predicted. Guessing whether you're at sitting vs walking with 90% accuracy is not very useful if most people are usually sitting. Actually, the article here doesn't even report the accuracy: neither the stdev error for scalar predictions, or the precision/recall and number of classes predicted for ordinal data. Actual results would go a long way to making the article meaningful. There's a growing number of these "computers can now predict..." articles, like "one email from you can tell your mood" or "your choice of snap filter reveals your age." Basically, in practice anything can predict anything, usually slightly better than random, so there's an infinite number of articles to write that sound shocking. If I had a bit of training data, I can easily write a script to predict everyone here's salary based on their comments using bag-of-words, and I bet I can do better than random guessing.