Research Rank

As you sleep and catalogue Sleep Styles, you will gain experience. This experience is different to your Pokémon Experience and goes towards your own Research Rank. This Rank will continue to increase and as you rank up, you will get a variety of rewards.

There are some benefits to this too. As your Research Rank goes up, the Dream Shards that Dream Clusters give you will increase in a scale based on your level and the maximum level your Pokémon can be will also increase, so until you reach a certain rank, your Pokémon will not be able to go beyond the cap.