In typography, a bouma (/ˈboʊmə/ BOH-mə) is the shape of a cluster of letters, often a whole word.
It is a reduction of "Bouma-shape", which was probably first used in Paul Saenger's 1997 book Space between Words: The Origins of Silent Reading, although Saenger himself attributes it to Insup & Maurice Martin Taylor.
However, considerable study and experimentation by cognitive psychologists led to their general acceptance of a different, and largely contradictory, theory by the end of the 1980s: parallel letterwise recognition.
[2] Since 2000, parallel letterwise recognition has been more evangelized to typographers by Microsoft's Dr Kevin Larson, via conference presentations and a widely read article.
[3] Nonetheless, ongoing research (starting from 2009) often supports the bouma model of reading.