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  2. Differential interference contrast microscopy - Wikipedia

    en.wikipedia.org/wiki/Differential_interference...

    This small phase difference is important for the correct function of DIC, since if the phase difference at the joint between two substances is too large then the phase difference could reach 180° (half a wavelength), resulting in complete destructive interference and an anomalous dark region; if the phase difference reached 360° (a full ...

  3. Standard addition - Wikipedia

    en.wikipedia.org/wiki/Standard_addition

    The amount of unknown and the total volume are the same across the standards and the only difference between the standards is the amount of analyte spiked. This leads to a linear relationship between the analyte signal and the amount of analyte added, allowing for the determination of the unknown's concentration by extrapolating the zero ...

  4. False positives and false negatives - Wikipedia

    en.wikipedia.org/wiki/False_positives_and_false...

    The false positive rate (FPR) is the proportion of all negatives that still yield positive test outcomes, i.e., the conditional probability of a positive test result given an event that was not present.

  5. Phase-contrast imaging - Wikipedia

    en.wikipedia.org/wiki/Phase-contrast_imaging

    The advantages of these methods compared to normal absorption-contrast X-ray imaging is higher contrast for low-absorbing materials (because phase shift is a different mechanism than absorption) and a contrast-to-noise relationship that increases with spatial frequency (because many phase-contrast techniques detect the first or second ...

  6. Semantic view of theories - Wikipedia

    en.wikipedia.org/wiki/Semantic_view_of_theories

    The semantic view of theories is a position in the philosophy of science that holds that a scientific theory can be identified with a collection of models.The semantic view of theories was originally proposed by Patrick Suppes in “A Comparison of the Meaning and Uses of Models in Mathematics and the Empirical Sciences” [1] as a reaction against the received view of theories popular among ...

  7. Contrast (statistics) - Wikipedia

    en.wikipedia.org/wiki/Contrast_(statistics)

    A simple (not necessarily orthogonal) contrast is the difference between two means. A more complex contrast can test differences among several means (ex. with four means, assigning coefficients of –3, –1, +1, and +3), or test the difference between a single mean and the combined mean of several groups (e.g., if you have four means assign ...

  8. Contrast effect - Wikipedia

    en.wikipedia.org/wiki/Contrast_effect

    A contrast effect is the enhancement or diminishment, relative to normal, of perception, cognition or related performance as a result of successive (immediately previous) or simultaneous exposure to a stimulus of lesser or greater value in the same dimension. (Here, normal perception, cognition or performance is that which would be obtained in ...

  9. Componential analysis - Wikipedia

    en.wikipedia.org/wiki/Componential_analysis

    Structural semantics and the componential analysis were patterned on the phonological methods of the Prague School, which described sounds by determining the absence and presence of features. On one hand, componential analysis gave birth to various models in generative semantics, lexical field theory and transformational grammar. On the other ...