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 characteristics was found in the samples.
Approximately 1,500 handwriting specimens were collected from across the United States, and they were 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 supported 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. The study found that 98.55 percent of handprinted characteristics and 97.39 percent of cursive characteristics had an independence correlation of under 0.2. These findings support the use of the product rule in general, but with noted caveats. Finally, this study provided frequency occurrence proportions for 776 handwriting and handprinting characteristics. (Publisher abstract modified)