While reading another HOW-TO book he reflects that he would rather need WHETHER-TO books/guides.
His refers to another statement, which makes sense to me:
“What separates the great innovator from the mere data gatherer is the ability to stop gathering data and think about what has been gathered.” (from **CrazyBusy: Overstretched, Overbooked, and About to Snap! Strategies for Handling Your Fast-Paced Life, by Dr Edward Hallowell, p 132.).
Yes, I do think I need a whether-filter. Do you?