This summary is not the rule. The rule text controls.
Here's a plain English summary of this rule:
Sometimes a law or court rule spells out exactly how strong the evidence needs to be for a judge to rule a certain way. But other times, no specific standard is mentioned. This rule fills in that gap.
When no standard is stated, the judge will use "preponderance of the evidence." This means a judge only needs to believe something is more likely true than not true, basically anything over a 50% chance. It's a lower bar than "clear and convincing evidence" or "beyond a reasonable doubt," which are used in more serious cases.
For anyone involved in a juvenile court hearing, this matters because it affects how hard the other side has to work to prove their case. If no other rule says otherwise, the judge just needs to find that one side's version of events is slightly more believable than the other side's.