The aim of this study was to analyze scientific conclusiveness of the most widely used queestionnaire for handedness determination, the Edinburgh Handedness Inventory (further referred to as EHI) by author R.C. Oldfield, The Assessment and Analysis of Handedness: The Edinburgh Inventory (1971).
During the analysis, EHI was subject to detail methodological analysis which uncovered fundamental failing in methodology, construction of the diagnostic instrument and in characteristic of psychometric properties of this diagnostic instrument