Reformulating the error messages to be more constructive

[hugolio]

Reducing the number of shown errors, and reformulating the error messages
(e.g. KnuteTerm message could be more helpful)

Error messages:

• “This concept is a “KnuteTerm”, so there should not be any search results.”

• Suggestion: Reformulate to show what a user has to do. “This concept groups a number of subconcepts. Choose a subconcept in the left panel to continue"

• “Note: Search for subject strings is currently experimental, and might not yet work as expected.”

• Suggestion: Perhaps remove this message?

• After clicking a keyword which is not in the current vocabulary (broad search): “Beklager, emnet «Amsterdam (Nederland)» ble ikke funnet i dette vokabularet.” / “Sorry, the subject «Amsterdam (Nederland)» was not found in the current vocabulary.”

• Suggestion: Perhaps do not make concepts that are not in the same vocabulary clickable, at least in "simple mode"

• “Det oppsto en ukjent feil.”

• Suggestion: reformulate.

• “How odd! Not a single document on that subject could be found using the current subject vocabulary. You could try expanding the search to a broad search.”

• Suggestion: reformulate: "No documents could be found in the current subject vocabulary. You could try expanding your search to a broad search.”

[hugolio]

Based on J. Nielsen, Usability Heuristic: "Error prevention" - "Even better than good error messages is a careful design which prevents a problem from occurring in the first place. Either eliminate error-prone conditions or check for them and present users with a confirmation option before they commit to the action."