ELHC 471 Game Design and Prototyping

// This is the main function that compares the learner's answer to the correct answer
function compareAnswers() {
    // Get access to Storyline's features
    var player = GetPlayer();

    // Get the learner's answer and the correct answer from Storyline
    var learnerAnswer = player.GetVar("Learner_Answer");
    var correctAnswer = player.GetVar("Correct_Answer");

    // Clean up both answers (remove extra spaces, make uppercase, ignore punctuation, etc.)
    var processedLearnerAnswer = processAnswer(learnerAnswer);
    var processedCorrectAnswer = processAnswer(correctAnswer);

    // Calculate how accurate the learner's answer is (0-100%)
    var score = calculateScore(processedLearnerAnswer, processedCorrectAnswer);

    // Check if the learner's answer is exactly correct or contains the entire correct answer
    var containsCorrectAnswer = (score === 100) || checkContainsCorrectAnswer(processedLearnerAnswer, processedCorrectAnswer);

    // Update the accuracy score in Storyline
    player.SetVar("Accuracy_Score", score);

    // Update whether the learner's answer is correct or contains the correct answer in Storyline
    player.SetVar("Contains_Correct_Answer", containsCorrectAnswer);

    // If the answer is completely wrong, briefly change the score to 1% and back to 0%
    // This helps trigger Storyline events even when the score doesn't change from 0%
    if (score === 0 && !containsCorrectAnswer) {
        brieflyChangeScore(player);
    }
}

// This function cleans up the answers for easier comparison
function processAnswer(answer) {
    // Remove all punctuation (including within words), convert to uppercase, and remove extra spaces
    return answer.replace(/[.,\/#!$%\^&\*;:{}=\-_`~()]/g, "").trim().toUpperCase().replace(/\s+/g, " ");
}

// This function calculates how accurate the learner's answer is
function calculateScore(learnerAnswer, correctAnswer) {
    if (learnerAnswer === correctAnswer) {
        return 100; // If the answers match exactly, give 100%
    } else if (learnerAnswer.includes(correctAnswer)) {
        return 90; // If learner's answer contains the correct answer but has extra content, give 90%
    } else {
        // For partially correct answers, calculate a score based on how many correct words are present
        var correctWords = correctAnswer.split(" ");
        var matchedWords = correctWords.filter(word => learnerAnswer.includes(word));
        return Math.round((matchedWords.length / correctWords.length) * 80); // Max 80% for partial matches
    }
}

// This function checks if the learner's answer contains the entire correct answer
function checkContainsCorrectAnswer(learnerAnswer, correctAnswer) {
    return learnerAnswer.includes(correctAnswer);
}

// This function briefly changes the score from 0% to 1% and back
// It helps trigger Storyline events when the answer is completely wrong
function brieflyChangeScore(player) {
    player.SetVar("Accuracy_Score", 1); // Set score to 1%
    setTimeout(function() {
        player.SetVar("Accuracy_Score", 0); // Set score back to 0% after a very short delay
    }, 50); // 50 milliseconds = 0.05 seconds
}

// This line runs the main function when the script is executed
compareAnswers();