Disappointed

Disappointment is a personal problem in some sense and telling a child you're disappointed in them makes them responsible for your emotions as an adult with little understanding of how to proceed forward. All they know is I am the cause of some emotional upset or pain in this guardian or other adult who I [consciously or not] see as powerful.

Disappointment communicates deficiency and very little else, where a greater conversation could bring out productive answers or the results you're looking for.

Disappointment most effectively and generally says:

• I had an expectation of an event or person's behaviour
• My expectation was not met
• I am upset

Even more specifically, "disappointed" is often used to communicate:

• I had an expectation of an event or person's behaviour
  • I deem my expectation the best outcome or "good"
• My expectation was not met or you did not meet my expectation
  • For an individual, as someone who has not met my expectation you or your actions are something other than "good" (usually, "bad")
• I am upset
  • I am having a "negative" experience as a consequence of my expectations not being met
  • I am having a "negative" experience as a consequence of your not meeting my expectations
    • You are responsible or at fault for this outcome

Some ideas or questions "disappointed" doesn't address when thrown at children (or others) in isolation:

• Why was this expectation not met?
• Why was this expectation set?
• Was the other party aware of this expectation?
• Did the other party have the necessary materials, resources, abilities, or background to meet this expectation?
• Was this expectation set based on circumstances of reality?
  • Are you aware of all the circumstances of reality?
    • Your reality and the other party's?
• Was the expectation predetermined [before developing thorough understanding of the other party or even meeting them]?
• Was the expectation negotiated when new information was revealed?