The measurement
Same person. Same three questions. Same day. Four assistants.
One engine drew on twenty two distinct hosts. One drew on four. One drew on four. One drew on a single source, and that source was an internal redirect belonging to the company that makes the assistant rather than a publication anybody could read.
Why this matters more than the wording
People tend to judge these answers on tone: does it sound right, is it generous enough. That is the least useful thing on the screen, because the wording changes between runs and the sources are the part you can act on.
An answer built on twenty two sources and an answer built on one can read almost identically. One of them is resting on a great deal and the other is resting on very little, and only the citation list tells you which.
Two answers can sound equally confident while one is built on twenty two sources and the other on one.
So checking one assistant proves almost nothing
If you ask one assistant about yourself and the answer is fine, you have learned that one engine, on one day, was content. You have not learned what the other three say, and on our own measurement they differ enormously.
The same applies in reverse. An assistant that declines to answer, or answers thinly, is not evidence that nothing about you is available. It is evidence about that engine.
Our own check records an engine that could not be reached as a separate result from an engine that answered and did not name you. Those are different findings and collapsing them is how people get told the wrong thing. How to check it properly sets out the method.
What the gap does not tell you
We are not going to rank the four engines, and a single person's reading is not a basis for doing so. Which engine leans on most sources will vary by subject, by question and over time.
What is stable enough to act on is the shape: the four do not agree, so a reading worth having covers all of them, and the part worth fixing is the sources rather than the sentences.
24 September 2026, our own founder, three questions to each of four engines. All four named him on all three questions. Distinct sources behind the answers: 22, 4, 4 and 1.