I’ve never lifted a rhino. Never touched one. And I know it’s hard, almost impossible, to lift it with my single right hand. Alone. This might sound like an odd way to begin, but stay with me: this rhino is a metaphor for one of education’s most frustrating problems: how to grade fairly in team projects.

The Rhino and the Pizza

Imagine a project like hoisting a chubby rhino into your second-floor bedroom. It’s heavy work. Too much for one person. You need a team, maybe even a crane. Since it’s collaborative, someone inevitably does more, while someone else does less. Egalitarianism is a fantasy in teamwork.

Now, let’s swap out the rhino’s heliporting endeavour for something lighter: pizza. Whether you cut it into six slices or eight, if you and your friends finish the whole pizza, you’ve eaten 100% of it. The shape doesn’t matter. The crust doesn’t matter. What matters is that all slices add up to a whole.

Projects are the same. Whether it’s lifting a rhino or building a locomotive, the total work always adds up to 100%. The real question is: Who contributed how much to that 100%?

The 100% Law: A deceptively simple idea for fair teamwork grading

That’s where my One Hundred Percent Law comes in. No matter how big or small the project, the combined contributions of every team member must add up to 100%. From this single principle comes a grading framework:

1. Self + Peer Assessment: Each student rates themselves and their peers. All ratings must total 100%.

2. Instructor Assessment: The teacher also rates all members, totaling 100%.

3. Proportional Grading: A student’s grade is proportional to their contribution relative to the highest contributor, multiplied by the team’s overall grade.

This 4-minute system instantly reveals who carried the weight. And who coasted.

By applying this deceptively simple law, we can finally answer the age-old question: Who did how much? The result? Grades based on the actual contribution of every team member. This approach works in colleges, high schools, even junior classrooms.

It ends disputes over freeloaders. It terminates resentment among hard-working students.

And yes, you might be thinking: But what if students collude?

Scenarios like collusion, favoritism, or even bullying are more complicated. But we can handle them by adding a statistical layer called Bayesian adjustment (a topic I’ll unpack in my next article).

Why It Matters

Fair grading isn’t just about numbers. It restores trust in teamwork. It motivates students to pull their weight. It gives peace to teachers tired of arbitrating group drama. In other words: lift the rhino together, and everyone earns their share of credit.

I explore this method in detail in my book, Who Lifts the Rhino? It’s a short, practical guide for educators to bring fairness back to teamwork grading.

Want to put it into action? Onteam automates this method in 4 minutes flat. No rhino cranes required.

Have you faced unfair teamwork grading? Share your story in the comments. Let’s lift this rhino together.

Coming Soon: Part 2

 In my next post, I’ll unpack Bayesian adjustment — a simple, powerful way to catch collusion, favoritism, and bias in teamwork grading (without the math headache).