These concepts are not unlike some of my own ideas about practicing. I might add a few thoughts to these components.
During the discovery phase pay particular attention to the fingerings, bowings, etc. There is usually a lot of information to remember. Don't get in a hurry to learn it all at once. Take it in small chunks. The article also mentions singing or vocalizing the music. This is key! Whatever music you want to play you should listen to that music all the time. It needs to be firmly in your head before you start trying to practice it. It will get in your fingers much faster.
Their advice about repetition is spot on. Learn the music in small parts and slowly join the pieces together. Playing SLOW during this stage is super important. I wrote a blog post outlining how to practice slowly with a metronome a few years ago. They encourage playing a passage 3 times before moving. That's cool but I say go with what feels right. Sometimes it will be more, sometimes less depending on how hard the passage is for you.
This is where you're looking for mistakes. What do you do if you're making mistakes? Ask why. In this older blog post I describe ways to fix those mistakes you might be having. Using a recording device is the best to hear what you need to fix.
Another excellent article from Musician's Way. Happy Practicing.