Imagine the world as a white canvas with black spots on it. Over that, lay a mesh made of squares and describe what shows through the mesh. We are describing the world, but as it shows through the mesh. Change the mesh in size or in shape and we have a new description of the world.
Now, these descriptions are useful and allow us to do things, but they are not truth, they are description. They may be highly accurate in their descriptions of an actual world, but they are still descriptions. It’s how science functions and is how science progresses and changes. It also is why I advocate an argumentative approach to validity in the use of scientific structures like assessment or the use of evidence. Old forms of validity (dependent on criterion validity) and much of the current discussion of evidence-based approaches is about the accuracy in certain forms of description. But we must also allow for discussions of the mesh (to return to the metaphor). As in construct validity, any discussion of how the world is must also include a discussion of how the mesh interact with the world to create the description.
In addition to methods like random controlled trials (RCTs), there is also a need for research into how we understand and rethink the assumptions and things that are sometimes unexamined in research. RCTs are very good at helping us do things with very accurate descriptions (like describe linear causal processes). We also need research that uses other meshes that will allow us to understand in new ways and facilitating our ability to do new and different things; to make progress.