A point vs a line
The danger of seeing only the current data and not the history of the data.
Within the visualization of data there are two main ways to see it: In a photo at a specific moment or in its evolution over time. Seeing the data or the value in a single moment is like seeing an isolated point.
Since the ancient greeks who left us geometry as a powerful tool for humanity, the point was visualized within a cartesian plane. The point, along with the line and the plane are the fundamental elements of geometry. The concept of point as a geometric element was born in the ancient greek conception of geometry in the Treatise Euclid´s Elements, where its definition is fascinating: “The point is what has no place”. That is why the cartesian plane is so important, which ends up being the context of the data since that time. The point exists to locate it on a plane!
If we look at the data in a time series, you can see where the points are going and it turns out to be like a path. And depending on the trend, this path may be good or it may be a path to the abyss depending on the situation that is being observed.
A single point does not generate a trend. We do not know where it is moving. We only know how it is today. And if that value or that point is within an acceptable range, then a decision maker will be calm. For example, if a machine reports a temperature within the range determined for acceptable performance, the machine appears to be performing well because it is not overheating. And if the machine for three years in six different measurements reports values within the range, when viewing each data at each specific moment, there will be no need to worry. But if those six points within the range, located on a plane, go upwards, that is, the temperature is rising, could we be just as calm?
In the case of this machine with six values in range but trending upward, the end of the story could be a seventh data out of range and a machine that overheats and breaks down.
In the health sector, six values within the range that are moving away from one of its limits and whose trend is not observed in time, to what end of history could it lead? A damaged human machine with a decrease in its quality of life or worse, without life.
So, written reports full of text and a few numbers only of the current time, with zero context, trend, or history, are a danger… more for humans than for machines.
