[evan_au]

Couldn't the evidence in a graph, be presented in "digital" format, ie as just tables of numbers? Is it because graphs make it easier to see the underlying mathematical processes.

Yes, humans are a very visual species.
- We have the unusual visual quirk that we can see things that don't change, which makes the whole "reading a book" possible.
- As I understand it, for most species, things that don't change do not generate an image.

Graphs work well in 2D.
- They can be extended to 3D on a page for some sets of data
- but I think 3D data would be explored more easily with virtual reality headsets
- I have seen one presentation (as a movie) that worked through data in more than 3 dimensions (I think  it may have been 8 dimensions?). But that was geometrical data, so it was (sort of) possible to see geometrical patterns emerge as the view switched between hyperplanes. I don't this would work nearly so well for data that was noisy in multiple dimensions, as you would only see part of the pattern and part of the noise.

The one I saw was a bit more colorful than this one:

As BC said, regression can find patterns in multi-dimensional data that we wouldn't be able to visualise.

[vhfpmr]

Couldn't the evidence in a graph, be presented in "digital" format, ie as just tables of numbers?  From which conclusions could be arrived at.

The picture on your TV is broadcast as a list of numbers, would you rather it was displayed like that?

[Eternal Student]

Hi.

Is it because graphs make it easier to see the underlying mathematical processes?

  Good answers have already been made based on using graphs to visualise data and why human beings tend to want to do this.

   Here's an alternative answer:
    Through time, the use of conventional graphs, bar charts, scatter diagrams etc.  has become a highly evolved and internationally utilised artifact of mathematics.  So much so that is a useful, if conceptually abstract, form of communication in it's own right.   Teaching children in school to use graphs is no different to teaching people a common language.
    We could teach children to use tabulated data and numerical statistics but it would be harder to understand and frequently misunderstood.  Sufficiently difficult to use and understand that it would fail as a mode of communication between two people often.

[vhfpmr]

Numeric data and graphs are not really alternatives, they're complementary, one to analyse, the other to visualise. Two different tools for two different jobs, like a hammer and a screwdriver. You wouldn't knock screws in with a hammer on the grounds that it must be the right tool because it works so well on nails, or just to prove it can be done.

[evan_au]

Graphical data draws on the considerable visual processing capability in the rear of our brains, with enormous parallel-processing ability.
- You can (sometimes) identify trends in hundreds of data points at a glance
- A fraction of your brain's 25W of power consumption can be used to navigate a car (while holding a conversation with the person next to you)
- The computer in a self-driving car typically consumes about 1,000 W
- This visual processing is not very precise - maybe to within 1%, but it becomes pretty automatic and unconscious (ie "effortless") after some training

Tables of numbers utilise the number processing ability which is laboriously learned in school, using the conscious processing capabilities at the front of our brains.
- This is mostly serial processing (slower)
- Most people can only do one conscious activity at a time - try holding a conversation while mentally adding up a table of numbers!
- Most people can only remember a couple of numbers at once. Trends may not be apparent when looking at only 2 or 3 numbers at once
- A table of numbers can give enormous precision (some quantities in physics are known beyond 8 digits; many quantities in a national budget are specified to 8 digits)
- But it's hard work!
- Few people could multiply two 8 digit numbers together and get the right answer - but your laptop is probably capable of doing a billion or more such calculations per second.

I have no doubt that some skilled mathematicians and accountants can scan a column of numbers and pick the trends and the outliers, but these are the exceptions

[vhfpmr]

It occurred that steganography is a case when numerical analysis is more likely get you further than looking at the picture.

[nicephotog]

Regression as explained by Harvard's business article is the use of a number of factors  (named variables or the main related variable that is consistent) that achieves the best relationship to an outcome as a particular "result" thereby being given a point that it gives more accurate prediction to acquire the result (think sales graphs).
Why i've always been a user of "mode average" by adjusting the band in which the mode set falls between by re calibrating the upper and lower boundary parameters that are possible (not merely the band -  when your outer parameters (boundaries) of what you measure cannot be moved (being unreal - truth bending) to achieve a small tight ratio -where are these weird typos coming from- with multiple results then there is no mode in the result boundaries that would allow either prediction or accuracy).

shouldn't add this but its not bad either...