Question Behavior

When developing a Qbehavior plugin in Moodle, the most important aspect is managing how questions behave during attempts in a quiz. A question behavior plugin controls how a user interacts with a question, how responses are processed, and how feedback is provided. It determines the user experience during quizzes, such as whether users can retry incorrect answers, how immediate feedback is shown, and how marks are adjusted based on responses.

Key Aspects of Developing a Qbehavior Plugin

Plugin Structure and Location A Qbehavior plugin is located in the /question/behaviour/ directory. When you create a new plugin (e.g., mybehavior), it will be structured like this:
```
/question/behaviour/mybehavior/
```
Essential files include:
- behaviour.php: This is the core file that defines how the question behaves.
- lang/en/qbehaviour_mybehavior.php: This file contains language strings for the plugin.
- version.php: Metadata about the plugin's version and Moodle compatibility.
behaviour.php: Core Logic of the Plugin

The heart of a Qbehavior plugin is the behaviour.php file. This file extends the base class question_behaviour and implements specific methods that define the behavior of the question during a quiz attempt.
- Response processing: Determines how student responses are handled (e.g., whether multiple attempts are allowed, how answers are graded).
- Feedback: Manages how feedback is provided to the user (immediate, deferred, or based on multiple tries).
- Question state transitions: Controls how a question moves between states (e.g., unanswered, partially answered, correct, incorrect).
Example:
```
class qbehaviour_mybehavior extends question_behaviour {
    public function process_action($submitteddata, $response) {
        // Logic for handling the user's submission and moving to the next state.
    }

    public function adjust_fraction($fraction) {
        // Logic for adjusting the score based on the user's attempts or responses.
    }
}
```
Key Methods to Implement When developing a Qbehavior plugin, there are several critical methods you need to implement to define how the behavior works. The most important ones include:
- process_action($submitteddata, $response): Defines how the system processes the student's answer submission and evaluates the state.
- is_complete_response($response): Determines whether the user's response is considered complete, which is important for handling submissions.
- adjust_fraction($fraction): Adjusts the score or grade based on the number of attempts or quality of the response.
- is_graded(): Specifies whether the question is graded immediately or deferred until the end of the quiz.
These methods collectively control how the question transitions between states (e.g., whether the user can try again after an incorrect answer or receive partial marks).
States and Transitions A critical part of developing a Qbehavior plugin is managing the question states and state transitions. Each question can go through various states, such as todo, complete, graded, and invalid. The behavior plugin is responsible for handling these transitions based on user interaction.
- States like question_state_todo, question_state_complete, question_state_graded, etc., are important for controlling what happens at each stage of the quiz attempt.
- For example, in adaptive behavior, a student may be allowed to submit multiple attempts at the same question, while in deferred feedback, they submit answers only once.
Example of handling state transition:
```
public function process_action($submitteddata, $response) {
    if ($this->is_correct_response($response)) {
        return question_state::graded_state_for_fraction(1);
    } else {
        return question_state::todo();
    }
}
```
User Interaction and Feedback A significant focus of a Qbehavior plugin is how feedback is provided to users during the quiz.
- Immediate Feedback: Some behaviors provide feedback right after the user submits their answer, showing whether they were correct or incorrect (e.g., immediate feedback behavior).
- Deferred Feedback: Feedback is provided only after the quiz is completed (e.g., deferred feedback behavior).
- Partially Correct: Some behaviors allow partial marks and provide feedback after multiple attempts (e.g., interactive behavior).
Example:
```
public function get_feedback($response) {
    if ($this->is_correct_response($response)) {
        return new question_feedback('Correct!', 1);
    } else {
        return new question_feedback('Try again!', 0);
    }
}
```
Grading and Fraction Adjustment Another important part of developing a Qbehavior plugin is how marks (fractions) are assigned based on user responses. You might want to adjust the score depending on how many attempts a student made or how close their response is to being correct.
- In some behaviors, full marks are awarded for the correct answer on the first try, and partial marks for subsequent attempts (adaptive behavior).
- In others, the score may remain the same regardless of the number of attempts (deferred feedback).
Example:
```
public function adjust_fraction($fraction) {
    // Decrease the fraction for each additional attempt.
    $attempts = $this->get_num_attempts();
    return max(0, $fraction - ($attempts * 0.1));
}
```
Handling User Actions and Validation The Qbehavior plugin defines how user actions like submitting an answer or trying again are processed.
- Validation of responses: Your plugin must validate the user's submission to ensure it's a valid response for the question type.
- Partial or multiple attempts: Depending on the behavior, the user may be allowed to attempt the question multiple times.
Example:
```
public function process_action($submitteddata, $response) {
    if ($this->is_valid_response($submitteddata)) {
        // Save the user's response and transition to the appropriate state.
    } else {
        return question_state::invalid();
    }
}
```
Performance Considerations Performance is important, especially when many students are taking a quiz simultaneously. Qbehavior plugins should be optimized for efficiency:
- Minimize database queries during state transitions.
- Use caching where necessary.
- Avoid unnecessarily loading large amounts of data.
Testing and Compatibility Testing is critical to ensure that the Qbehavior plugin works correctly across different question types and quiz scenarios.
- Unit tests: Write unit tests to cover the various question behaviors, especially for edge cases like invalid submissions, retries, and multiple attempts.
- Compatibility: Ensure that your plugin is compatible with various question types (e.g., multiple choice, short answer) and integrates smoothly with Moodle’s grading and feedback systems.

Example of Developing a Qbehavior Plugin: Adaptive Mode

Suppose you are developing a custom adaptive behavior that allows students to submit multiple attempts for a question, but with diminishing marks for each incorrect attempt.

Core Logic (behaviour.php)

The process_action() method checks if the student's response is correct or incorrect.
If correct, the question is marked as complete and fully graded.
If incorrect, the user can retry, but with a reduced mark (e.g., 10% less for each wrong attempt).

Example:

class qbehaviour_adaptive_custom extends question_behaviour {
    public function process_action($submitteddata, $response) {
        if ($this->is_correct_response($response)) {
            return question_state::graded_state_for_fraction(1);
        } else {
            return question_state::todo();
        }
    }

    public function adjust_fraction($fraction) {
        $attempts = $this->get_num_attempts();
        return max(0, $fraction - ($attempts * 0.1));
    }
}

User Feedback

The user receives feedback after each attempt, with immediate feedback on whether the response was correct or incorrect.

public function get_feedback($response) {
    if ($this->is_correct_response($response)) {
        return new question_feedback('Correct! Full marks.', 1);
    } else {
        return new question_feedback('Incorrect! Try again.', 0);
    }
}

Conclusion

The most important aspect of developing a Qbehavior plugin in Moodle is defining how questions behave during quiz attempts. This involves managing question state transitions, processing user responses, providing appropriate feedback, and handling grading or score adjustments. By extending the core behavior classes, customizing the user interaction flow, and ensuring optimal performance, you can create a Qbehavior plugin that enhances the quiz-taking experience in Moodle.