PubMed · 5094949
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
R L Fitzpatrick. 1971. Improved x-ray topography.. https://doi.org/10.1063/1.1685383
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
A novel monochromatic optical density meter is described for use with radiographic films. The principles of the instrument are outlined together with a brief description of the construction of a prototype model. The calibration of the meter shows high accuracy (r = 0.9999) in the optical density range 0-1.5 OD when compared to standard neutral density filters.
The belief that the level of measurement (nominal, ordinal, interval, ratio) achieved in the data constrains the type of statistic that may be used legitimately for analysis is examined in general, and in an optometric-vision science context. Theoretical considerations indicate that statistical statements about the data may be made independently of the level of measurement, and that although researchers must be concerned about the quality of their measurement, the role of measurement theory is in the interpretation of the meaning of the investigation's results as a whole not in the governance of the choice of statistic. Empirical studies indicate that measurement considerations can be ignored for the purposes of testing the null hypothesis with little or no resultant error. Finally, adherence to the belief that level of measurement considerations limits statistical choice would result in the use of generally less powerful statistical tests--an undesirable and, all things considered, an unwarranted consequence.
Explore the source record for details and available documents.