I'd reuse the instance methods you already have in this class, so you don't have multiple places to change things in the future e.g. if you decide radio inputs should be "Radio" instead of "Radio Buttons":

```
  if select_list? || select_radio?
    # blah
  end
```

Or, even better, I might create an instance method called `#multi_select?` and then use that in the `before_save` class method, like this:

```ruby
before_save :ensure_score_levels, :if => :multi_select?

def multi_select?
  select_list? || select_radio?
end

private

def ensure_score_levels
  if score_levels.count <= 1
    errors.add(:assignment_type, "To use the selected method of quick grading you must create at least 2 score levels")
  end
end
```

None of this is super important, just some thoughts.