models.py

class ResponseType(models.Model):
    # If you want people to rate others' responses, for instance. This
    # provides context on why this specific pattern is useful. Also,
    # consider aggregate functions over multiple data types.
    rating = models.PositiveIntegerField()

class StringResponseType(ResponseType):
    value = models.CharField(max_length=128)

class BooleanResponseType(ResponseType):
    value = models.BooleanField(default=False)

class MultipleChoiceResponseType(ResponseType):
    result = models.ForeignKey(ResponseType, null=True)

class MultipleChoiceOption(models.Model):
    response = models.ForeignKey(ResponseType)
    response_type = models.ForeignKey(MultipleChoiceResponseType,
                                         related_name='options')

class Survey(models.Model):
    name = models.CharField(max_length=64)
    description = models.TextField()    

class Question(models.Model):
    class Meta(object):
        order_by = ('survey','order',)

    query = models.TextField()
    order = models.PositiveIntegerField(max_length=2)
    survey = models.ForeignKey(Survey)

class Response(object):
    class Meta(object):
        order_by = ('user')
        unique_together = (('user', 'question'))

    user = models.ForeignKey(User)
    question = models.ForeignKey(Question)

    # Allows responses of different types. Boolean, String, Integer. etc.
    answer = models.ForeignKey(ResponseType)