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  2. Shewhart individuals control chart - Wikipedia

    en.wikipedia.org/wiki/Shewhart_individuals...

    The value 3.267 is taken from the sample size-specific D 4 anti-biasing constant for n=2, as given in most textbooks on statistical process control (see, for example, Montgomery [2]: 725 ). Calculation of individuals control limits

  3. Sample size determination - Wikipedia

    en.wikipedia.org/wiki/Sample_size_determination

    The sample size is an important feature of any empirical study in which the goal is to make inferences about a population from a sample. In practice, the sample size used in a study is usually determined based on the cost, time, or convenience of collecting the data, and the need for it to offer sufficient statistical power .

  4. x̅ and s chart - Wikipedia

    en.wikipedia.org/wiki/X̅_and_s_chart

    The sample size is relatively large (say, n > 10— ¯ and R charts are typically used for smaller sample sizes) The sample size is variable; Computers can be used to ease the burden of calculation; The "chart" actually consists of a pair of charts: One to monitor the process standard deviation and another to monitor the process mean, as is ...

  5. x̅ and R chart - Wikipedia

    en.wikipedia.org/wiki/X̅_and_R_chart

    The sample size is relatively small (say, n ≤ 10— ¯ and s charts are typically used for larger sample sizes) The sample size is constant; Humans must perform the calculations for the chart; As with the ¯ and s and individuals control charts, the ¯ chart is only valid if the within-sample variability is constant. [4]

  6. Stereoscopic acuity - Wikipedia

    en.wikipedia.org/wiki/Stereoscopic_acuity

    A good procedure is a chart, analogous to the familiar Snellen visual acuity chart, in which one letter in each row differs in depth (front or behind) sequentially increasing in difficulty. For children the fly test is ideal: the image of a fly is transilluminated by polarized light; wearing polarizing glasses the wing appears at a different ...

  7. Depth perception - Wikipedia

    en.wikipedia.org/wiki/Depth_perception

    A related phenomenon is the visual system's capacity to calculate time-to-contact (TTC) of an approaching object from the rate of optical expansion – a useful ability in contexts ranging from driving a car to playing a ball game. However, the calculation of TTC is, strictly speaking, a perception of velocity rather than depth.

  8. PS Power and Sample Size - Wikipedia

    en.wikipedia.org/wiki/PS_Power_and_Sample_Size

    A description of each calculation, written in English, is generated and may be copied into the user's documents. Interactive help is available. The program provides methods that are appropriate for matched and independent t-tests, [ 2 ] survival analysis, [ 5 ] matched [ 6 ] and unmatched [ 7 ] [ 8 ] studies of dichotomous events, the Mantel ...

  9. Wikipedia:Graphs and charts - Wikipedia

    en.wikipedia.org/wiki/Wikipedia:Graphs_and_charts

    Livegap Charts creates line, bar, spider, polar-area and pie charts, and can export them as images without needing to download any tools. Veusz is a free scientific graphing tool that can produce 2D and 3D plots. Users can use it as a module in Python. GeoGebra is open-source graphing calculator and is freely available for non-commercial users.