The premise of this study was to take a valid population sampling of handwriting and handprinting and assess how many times each of the predetermined characteristic is found in the samples. Approximately 1500 handwriting specimens were collected from across the United States and pared to obtain a representative sample of the U.S. adult population according to selected demographics based on age, sex, ethnicity, handedness, education level, and location of lower-grade school education. This study has been able to support a quantitative assessment of extrinsic and intrinsic effects in handwriting and handprinting for the six subgroups. Additional results include analyses of the interdependence of characteristics. This study found that 98.55% of handprinted characteristics and 97.39% of cursive characteristics had an independence correlation of under 0.2. The conclusions support use of the product rule in general, but with noted caveats. Finally, this study provides frequency occurrence proportions for 776 handwriting and handprinting characteristics.

The premise of this follow-up sister study to "Measuring the Frequency Occurrence of Handwriting and Handprinting Characteristics" was to collect a representative population sampling of numerals and assess how many participants utilize each of the predetermined characteristics as found in their specimens. A total of 1410 handwriting specimen forms were collected from across the United States and pared to 1025 to obtain a proper representative sample of the U.S. adult population based on the same demographics used in the original 2017 study. This study provides frequency of occurrence proportions and 95% confidence limits for 25 handwritten numeral characteristics. A total of 277 intercharacter pairs of handwritten numeral characteristics were cross-analyzed for interdependence. The results were that 72.92% of all intercharacter pairs had a coefficient of correlation between -0.2 and +0.2 in this study.