When using the built-in scoring variables for questions it is important to understand exactly how Opus calculates which scores it thinks you want to include in variables such as the total possible score as this will affect the overall percentage calculations.
When setting any single-select question Opus will assume the answers are either/or and will therefore take only ONE score from the list of answers. It will always choose the highest score. This is intended to allow for weighted questions where fuller or more accurate answers get a better score.
So if you have a text input question and check for root (for 1 point) or root hair cell (for 2 points) The total score for that question will be 2 points.
Note:
Remember that despite its name Multiple Choice question types only requires a single answer so is a single-select question. On the other hand Multiple Response question types will score multiple answers.
Some questions expect multiple answers and in this case Opus will combine ALL scores from the answers as it expects that all answers should be included.
However this means that you cannot include alternative answers with different scores as Opus will include all of them in the total score. So, for example, the answer to a question about plant nutrition might be "absorbs minerals and water from the soil" and you might want one answer to score for including "minerals" and another for including "water" and another for "soil".
You realise that a student might use "nutrients" instead of minerals. You can set a check "minerals OR nutrients" and either will score the point but you cannot put nutrients in another answer with slightly less points than minerals because Opus will consider both scores can be scored and therefore include them in the total available score which slightly skews the overall result.
When you need the full flexibility the solution is to use a combination of question objects so as to control the scoring exatly as you require.
You can have more than one question on a page and the question object does not need to contain any content so the overall design can appear to be only one question with multiple answers.
Examples of how to create sophisticated answers and scores are provided in the tutorials and examples on our website.