How Roxxem Measures Student Proficiency—and Uses It to Power Personalized Learning

By Dr. Jingjing Ren, Roxxem Head of AI

At Roxxem, we believe students learn more effectively with feedback. That’s why we’ve built an automatic user proficiency assessment system that not only measures where students are—it adapts to how they learn and guides them to the next step. 

This post explains how our proficiency scoring works, how it fuels personalized learning and real-time feedback on our platform.

Why This Matters

Language learning can feel overwhelming when content is too advanced, or disengaging when it’s too easy. Our AI-powered scoring system helps learners stay in the sweet spot—challenged but confident—and gives teachers tools to know each student in depth.

How We Measure Proficiency - Activity to Mastery Score

On Roxxem, students naturally engage in various activities - like games, lessons and homework. These activities generate valuable data about where students get right or wrong, reflecting the mastery of their skill levels. 

Instead of asking students to sit through expensive and time‑consuming exams, we convert this existing data into Roxxem scores. Specifically, we aggregate the accuracy on easier, at-level, and harder content from a student’s most recent set of activities. And we want the students to score high in each content category to master the current level and move on to the next. 

As long as students are active on Roxxem, their score updates continuously, giving both students and teachers real‑time insights. 

Figure 1. Example student progress dashboard

How do we know which content is easy or hard for students?

All of our content - videos, questions and games - is rated by our in-house AI models in collaboration with language experts. Each rating maps to a difficulty level at a scale of 1-10, equivalent to the Common European Framework of Reference for Languages (CEFR) and American Council on the Teaching of Foreign Languages (ACTFL) proficiency levels as follows:

Pre-A1 / Novice Low

A1 / Novice Mid

A2 / Novice High

A2+ / Intermediate Low

B1 / Intermediate Mid

B1+ / Intermediate High

B2 / Advanced Low

B2+ / Advanced Mid

C1 / Advanced High

C2 / Superior

The scale allows us to consistently align students’ work with recognized international proficiency standards. 

Time to Fill up the Three-Level Proficiency Bucket

Because all our content is rated, we can also assess the relative difficulty of Roxxem activities for each student. We categorize task difficulty into three buckets:

Below-Level: These are tasks set below the student’s current level. They check whether a learner still remembers and can apply foundational knowledge. Strong accuracy here shows solid retention. They count as a small portion of the final score. 

At-Level: These match the learner’s present level. Performance here is the most telling indicator of current proficiency and day‑to‑day learning progress. 

Above-Level: These introduce more advanced material. In reality, the slightly harder content is ambiguous and we encourage students to grow beyond their comfort zone. 

Figure 2. Proficiency Bucket. Students need to score perfectly in each bucket to reach 100/100.
The area represents the weight roughly. 

As illustrated in Figure 2, a student needs to fill up(=score high) content from each level to truly master their current level and advance. The overall mastery score works by stacking up weighted performance to a simple 1–100 scale. For example:

Score of 41 -> Early in the journey, still working on mastering 

Score of 85 -> Strong mastery of the current level, with progress into the next one.

You may notice that the biggest weight is content at the current proficiency level. We encourage students to master content at their current level and one level up. 

Rewarding consistency and level advancing

Roxxems starts from a self-reported level to score user proficiency. On a daily basis, the score will be updated to reflect students’ recent activities. We also build the mechanics to reward consistency – if students maintain strong performance over a long period of time, they may advance to the next level and tackle contents that suit them most. Normally if a student scores high (e.g. more than 90/100) for more than 10 days, they will advance to the next level.   

How We Use the Score

The score is not just a number - it drives the learning experience:

Personalized Learning Paths: Students get activities that fit their level, plus a bit of stretch to keep them growing.

Teacher Insights – Teachers see who’s excelling, who needs extra support, and who’s ready to advance. Over time, how each student is progressing. 

Right-Time Feedback – Students get study guidance/feedback that matches their level, making support clear and motivating.

The result: students stay engaged with “just right” content, while teachers gain confidence that every activity aligns with real proficiency.

Early Results from Roxxem Learners 

Since the internal launch of the Roxxem proficiency score, we have gathered 4 months of data (Jun - Sep 2025). Early findings show that for every additional hour spent in Roxxem, students improve by 4 points out of 100.

This means that, by studying 25 hours on Roxxem, students can expect to advance their language proficiency by one level!

This school year, activities have just resumed, and we’re excited to gather more evidence. Our goal is to bring richer insights and tools into teachers’ hands, supporting evidence‑based, personalized language learning.

We’ll continue refining the Roxxem proficiency score, expanding our data, and building more teacher-facing features. By combining AI, pedagogy, and real‑time insights, we aim to make learning not just more effective—but also more engaging and meaningful for every student.