A discipline is potentially relevant if the problem falls within its research domain but it is not known whether the discipline's experts have written about the problem. If they have not $($and the literature search will reveal this$),$ then the discipline is not relevant $($although more advanced researchers might still consider such a discipline$).$ If the discipline's experts have produced one or more insights into the problem, then the discipline is relevant.

This description accurately describes what you are trying to determine in:

Step $4-$ Conduct the Literature Review

Step $3-$ Identify Relevant Disciplines

Step $2-$ Justify an Interdisciplinary Response

Step $1-$ Define the Problem or State the Research Question