Different scientists developed different approaches to notation and documentation.
Some logged an abundance of data without organizing them too much. Their documents were filled with tables, spreadsheets, graphs and other forms of raw data. Someone who was well-versed in a particular field could easily read and decipher this complex data, but those who lacked the required expertise might as well be looking at pure gibberish! The flood of data could drown anyone trying to make sense of the chaos.