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  2. Positive and negative predictive values - Wikipedia

    en.wikipedia.org/wiki/Positive_and_negative...

    The positive predictive value (PPV), or precision, is defined as = + = where a "true positive" is the event that the test makes a positive prediction, and the subject has a positive result under the gold standard, and a "false positive" is the event that the test makes a positive prediction, and the subject has a negative result under the gold standard.

  3. Repeatability - Wikipedia

    en.wikipedia.org/wiki/Repeatability

    The following conditions need to be fulfilled in the establishment of repeatability: [2] [4] the same experimental tools; the same observer; the same measuring instrument, used under the same conditions; the same location; repetition over a short period of time. same objectives; Repeatability methods were developed by Bland and Altman (1986). [5]

  4. Test statistic - Wikipedia

    en.wikipedia.org/wiki/Test_statistic

    The above image shows a table with some of the most common test statistics and their corresponding statistical tests or models.. Test statistic is a quantity derived from the sample for statistical hypothesis testing. [1]

  5. Event (probability theory) - Wikipedia

    en.wikipedia.org/wiki/Event_(probability_theory)

    In probability theory, an event is a subset of outcomes of an experiment (a subset of the sample space) to which a probability is assigned. [1] A single outcome may be an element of many different events, [2] and different events in an experiment are usually not equally likely, since they may include very different groups of outcomes. [3]

  6. Compositional data - Wikipedia

    en.wikipedia.org/wiki/Compositional_data

    In geology, a rock composed of different minerals may be a compositional data point in a sample of rocks; a rock of which 10% is the first mineral, 30% is the second, and the remaining 60% is the third would correspond to the triple [0.1, 0.3, 0.6]. A data set would contain one such triple for each rock in a sample of rocks.

  7. Law of total expectation - Wikipedia

    en.wikipedia.org/wiki/Law_of_total_expectation

    The proposition in probability theory known as the law of total expectation, [1] the law of iterated expectations [2] (LIE), Adam's law, [3] the tower rule, [4] and the smoothing theorem, [5] among other names, states that if is a random variable whose expected value ⁡ is defined, and is any random variable on the same probability space, then

  8. Average treatment effect - Wikipedia

    en.wikipedia.org/wiki/Average_treatment_effect

    In a randomized trial (i.e., an experimental study), the average treatment effect can be estimated from a sample using a comparison in mean outcomes for treated and untreated units. However, the ATE is generally understood as a causal parameter (i.e., an estimate or property of a population ) that a researcher desires to know, defined without ...

  9. Stratified sampling - Wikipedia

    en.wikipedia.org/wiki/Stratified_sampling

    Proportionate allocation uses a sampling fraction in each of the strata that are proportional to that of the total population. For instance, if the population consists of n total individuals, m of which are male and f female (and where m + f = n), then the relative size of the two samples (x 1 = m/n males, x 2 = f/n females) should reflect this proportion.