Recent content by Miner

  1. Miner

    Which hypothesis test to use to compare two lab tests?

    Here are the A vs. B comparisons. Again, the equivalence limits were arbitrarily chosen by me. You need to decide what these should be.
  2. Miner

    2-way ANOVA p-value output

    I agree with Karabiner. Statistical significance only means that the effect is large RELATIVE TO the experimental error. It does NOT mean that it is of any practical importance. Small p-values can occur, as Karabiner said, from very large sample sizes, or where the experiment deliberately...
  3. Miner

    2-way ANOVA p-value output

    Other than the fact that they are extremely small (p<<<<<<<< 0.05), you have taken them out of context, so we cannot explain more than that. Note: e-16 is scientific notation indicating that the decimal has been shifted 16 spaces to the right (e.g., 1e-5 = 0.00001).
  4. Miner

    Which hypothesis test to use to compare two lab tests?

    There are several options. You can use a Bland-Altman plot, a gauge linearity and bias study, and a paired equivalence test. Attached are examples of each. NOTE: On the equivalence test, you have to define equivalence limits. These are the limits at which there is no practical difference...
  5. Miner

    Time Series Analysis

    What is your question?
  6. Miner

    How do I analyze data to find points where there is a "significant" increase in the "y" variable.

    Are you looking to determine when is a shift in X large enough to be seen past the prediction error in Y?
  7. Miner

    Limits of agreement and Bland Altman plot

    I recommend the Limits of Agreement (mean difference +/- 1.96 StDev of differences), and the bias (plus any relationship between bias and size of measurement).
  8. Miner

    Variation in data

    Given that we are discussing organic systems that degrade over time, a reliability analysis method called degradation analysis comes to mind.
  9. Miner

    Time series

    Q1 - Because linear time series models are only designed to model linear trends in time series data. Q2 - You may also have exponential trends (read COVID-19) and s-curve trends. Q3 - You may have seasonality (additive or multiplicative) and cyclicity, none of which a linear model can...
  10. Miner

    Predictor

    You can still analyze it as continuous data, but it may show up as "chunky" on normality or residual plots. This can throw off the p-values in a normality test even though all the data points fall along a straight line. It may violate all sorts of assumptions and prevent you from publishing in...
  11. Miner

    Predictor

    This is probably due to round-up to fewer decimal places. Can you gain access to the data used to calculate the rates?
  12. Miner

    Regression Analysis without Excel or other program

    When you set the const to TRUE, the equation fit is y = b + mx. When const is set to FALSE, b is forced to zero and the equation that is fit is y = mx. Coefficient is m.
  13. Miner

    Test significant difference question

    You can still use a t-test for unequal variances.
  14. Miner

    one numerical and three categorical variables - which test?

    If I understand your study design correctly, you have one categorical independent variable (Water Source type), which has three levels, and one continuous dependent variable (distance). A 1-way ANOVA would be a good place to start. BTW, how do you know whether the water sources today are the...