The author notes that Tycho had made long series of observations partly under the astrological influence of Paracelsus, and allegedly regardless of earlier practice and states that Kepler estimated their error as \(4'\) or less (which compelled him to reject the Ptolemaic system of the world). She concludes that the notion of observational error was introduced into astronomy “somewhere between” Tycho, his instrument-makers and Kepler.
Her reasoning on the earlier history is wrong and her conclusion is therefore false. Ptolemy, Al-Biruni and Levi ben Gerson discussed errors of observation and knew how to minimize the influence of some of them. And even Ptolemy testified that he and Hipparchus before him had made regular observations, so that in this sense Tycho’s practice was not new. See my paper [The treatment of observations in early astronomy, Arch. Hist. Exact Sci. 46, No. 2, 153–192 (1993; Zbl 0787.01002)]. What was indeed new though was the much higher precision of the observations, necessitating their adjustments.
For the entire collection see [Zbl 1073.01001].