Open Answer

Respuesta de texto libre. Se evalua por similitud de caracteres o longitud minima.

Con correctAnswer (similitud Levenshtein)

Los textos se truncan a 500 caracteres para el calculo.

Feedback	Condicion
"Good answer!" + correct: true, score 8-10	similarity >= 0.8
"Your answer is partially correct." + correct: false, score 5-7	0.5 <= sim < 0.8
"Incorrect. Review the topic and try again." + correct: false, score 0-4	similarity < 0.5

{
  "exerciseId": "ex_003",
  "area": "writing",
  "type": "open_answer",
  "answer": "The cat is sleeping on the couch",
  "correctAnswer": "The cat sleeps on the sofa"
}

{
  "correct": false,
  "score": 7,
  "feedback": "Your answer is partially correct. Try to be more precise.",
  "metadata": { "area": "writing", "type": "open_answer" }
}

Sin correctAnswer (longitud minima)

Feedback	Condicion
"Answer received." + correct: true, score 10	longitud >= 10 caracteres
"Answer too short." + correct: false, score 0	longitud < 10 caracteres

{
  "exerciseId": "ex_003b",
  "area": "writing",
  "type": "open_answer",
  "answer": "I think dogs are loyal companions to humans."
}

{
  "correct": true,
  "score": 10,
  "feedback": "Answer received.",
  "metadata": { "area": "writing", "type": "open_answer" }
}

Sin correctAnswer solo se verifica que el usuario haya escrito algo. Para medir calidad, siempre incluir correctAnswer.