C.28.MR:8 - Common Anti-Patterns and How to Avoid Them

Recurring difficulty	What fails	Useful repair
Substitute a conditional probability for an intervention	Selection on an observation changes the input information while leaving the natural mechanisms in place.	Replace the targeted mechanism and derive under the intended input law, as in :5.1.
Force a displayed number and infer a changed load	The changed expression belongs to a measurement or interface that does not determine the physical quantity.	Locate the actuator or subject mechanism and compare the replacements, as in :5.2.
Freeze all other variable values	Downstream effects of the replacement disappear from the calculation.	Preserve the other functions and recompute their outputs.
Resample shared disturbances independently	The computation describes another dependence structure.	Generate the retained joint inputs and reuse their common causes.
Keep the first numerical branch	A chosen solution hides other admitted answers to the query.	Test whether alternatives change that answer; retain a bound or a stated selection condition when they do.
Use a static answer for a later controlled state	The intervention’s duration, event order or feedback has been omitted.	Add the relevant continuation rule and horizon before deriving the later result.