AI Coin Grading: A Conversation with Bill Eckberg

After the article "The Good and Bad of AI in Numismatics" (October 13, 2024), Bill Eckberg, President of Early American Coppers (EAC), and I engaged in a thoughtful exchange about the progress and challenges of AI in coin grading that readers may enjoy.

Below is a summary of our discussion:

Bill Eckberg:

Hi Justin,

I have always enjoyed your work on AI grading. It was fascinating to see the improvement in the accuracy of the AI model over time. I have a few questions:

Also, regarding your graph, the horizontal axis cannot be quantitative as portrayed. The numbers represent categories, not quantities of grade. The number of grade steps between VF-20 and EF-40 isn't the same as from Po-1 to VF-20, yet the spacing on the graph is equal. There are only three grade steps between VF-20 and EF-40, but at least five between Po-1 and VF-20. Similarly, between MS60 and MS65, there are four steps (MS-61, 62, 63, and 64), so the spacing should reflect that. A bar graph might avoid implying a quantitative horizontal axis.

Justin Hinh

Thanks for your thoughtful questions, Bill. Here are my thoughts:

Regarding the graph, a bar graph would be more accurate in representing each grade definitively. I'll use that from now on.

Additionally, I should have included a link to a video of Google Gemini analyzing a video recording of a coin. You can check out that video here. I'm excited about this development because, previously, AI could only analyze a coin with a few photos. But a video captures hundreds of frames and gives the AI much more data to work with.

Bill Eckberg:

After reviewing your data, it seems impossible to claim an optimal number of photos for consistent grading. The variations were all over the place. If the machine was learning, it should get more consistent with more images.

As a long-time collector, I believe there's no consistent difference between MS-69 and MS-70, except the price some are willing to pay. Testing those grades isn't useful, especially since your AI could only tell the difference as much as I can.

I'd like to see your AI grade series, like Lincoln cents, in grades from Good to Uncirculated. Can it differentiate VG from G, F from XF, XF from AU, or AU from MS? Those insights would be very useful. If that works, you could try different levels of VF and so on.

Keep at it.

Justin Hinh

I should clarify my goals and the results in the data file. I was testing two hypotheses with my limited set of coins:

The differences between testing grades like MS-69 and MS-70 are minimal and often subjective. I intended to see how the AI handles the full spectrum of grades, but focusing on more commonly traded grades like Good to Uncirculated would be more practical. I'll consider testing with series like Lincoln cents to see if the AI can differentiate between those grades.

Regarding the impact on third-party graders (TPGs), I've considered whether they're incentivized to adopt AI grading. While TPGs might eventually use AI for efficiencies like counterfeit detection, after exploring AI grading these past 14 months, I've concluded that AI won't be replacing human graders soon for several reasons:

These considerations are driven more by market forces than technical limitations.

Bill Eckberg

Thanks, Justin.

I agree with much of what you say but strongly disagree that TPGs deeply understand most series. That's true for commodity coins like Morgans and Saints but not for pre-1836 issues struck on a screw press. Many are rare enough that TPGs need to see them more often to improve their grading.

Justin Hinh

I knew I should have used a non-EAC example!

Bill Eckberg

Ha!

To read the earlier E-Sylum article, see:
THE GOOD AND BAD OF AI IN NUMISMATICS(https://www.coinbooks.org/v27/esylum_v27n41a21.html)