Plans.md

@@ -16,8 +16,21 @@ Representation of the model in memory should be a pure data structure and not ti
 
 In addition, I suspect writing modules for other file formats would not be easy in the current configuration.
 
+This principle is important for some of the following principles. It may be the change that needs to happen first.  There's a need to copy the model and attach it to measurements.  That's not obviously doable with the XML system.
+
+### Well defined interactions
+
+Interactions with the model should be as simple and few as possible to make things like update easy to implement.
+
 ## Measurements should have attached the exact configuration used to create them.
+
+Measurements should be traceable.  When a measurement is initiated, it should be based off a copy of the experiment model that's been divorced from the interface, and that copy should follow the measurement and be attached to the results.
+
 ## User should get immediate feedback.
+
+When the user takes an action, there should be immediate feedback, even it's just a "please wait" message.
+We'll use a view-model-controller system that serializes user actions into a queue handled by another thread, so that the UI thread can at least does not freeze.
+
 ## Error conditions should be obvious and clear.
 ## The view should be reflective of the model
 ## The interface should not punish the user.