There is a difference between one's car really having run out of gas and the car's gas gauge not sensing correctly. John Aaron claims he can tell one from the other, what's what, by way of somebody merely reading him what shows numbers wise on a car dashboard. John Aaron claims he can tell us if the gas tank is really empty simply by being read the numbers.......
Pretty "smart" guy that John Aaron....
Yes, there is. It is called pattern recognition. It is knowing the difference between signal and noise.
You think gauges -- and telemetry -- are simple binary conditions? Are you carrying a mental model here that what they are staring at is the equivalent of the "check engine" light on an automobile?
There's a cute little single-board microcomputer called the Arduino, built around the AVR series micros from ATmel. The boards typically have a couple of status LEDs soldered in to the input and output of the built-in UART -- aka the serial data communication lines.
Anyone who has played with an Arduino for more than a day can recognize just by the pattern of the blinking the difference between a successful program load and a hang. I use mine mostly for MIDI communication, and I can easily tell the difference between note events, CC events, and MIDI device status.
In none of these cases am I looking at the hex dump; I am only looking at the pattern by which an LED blinks.
Or the way, when you are using a VOM, the reading jumps around from poor probe contact and accidental circuit through your own fingers. You learn to see the difference, and how to sort out the real value being read from the spurious lunges.
This is what people do. Or, rather, trained and experience people. They look beyond the "Broken/Not Broken" to read the patterns in how the sensor/data is displaying.
Oh, another good example...a sphygmomanometer. The art of using one is to detect a pattern arising to detectability through the otherwise descending reading.
