Recent content by hlsmith

  1. hlsmith

    How would you test this

    Are these like the weighing stations?
  2. hlsmith

    Probability Distribution of Cars Sold

    Can you post the exact original question in its entirety! Have you covered the Poisson distribution in class?
  3. hlsmith

    How would you test this

    Not following what this is, "reduction to damage to the road and safety violations from increasing the number of inspectors?" Law enforcement agents or people that go out and inspect bridges?
  4. hlsmith

    Censored data

    I think literature may be more robust if you call this loss-to-follow-up, which falls under selection bias. If you can get a random sample of these individuals there can be weighting or Bayesian methods to correct for it.
  5. hlsmith

    Testing mathematical relation in dataset

    You gotta tell us where these data are from to better help us figure out things or tell you if a process already exists. That and I kinda want to make sure this isn't some wonky conspiratory hoax, like numbers in the bible.
  6. hlsmith

    Model Fit in AMOS

    Yeah I was skimming Shaddish, Cook, Campbell yesterday and saw that!
  7. hlsmith

    Assessing Concurrent Validity

    @spunky
  8. hlsmith

    Which t test to use, is it even applicable?

    Have you done the histogram, yet? What is your dependent variable? Willingness. So it is willingness explained by age. This would result in a multinomial logistic regression, but you need to visualize it first with histograms to see what the relationship looks like. If it is bimodal, you may...
  9. hlsmith

    Model Fit in AMOS

    Remind me what AMOS is? I was thinking it was for time series.
  10. hlsmith

    Which t test to use, is it even applicable?

    Not sure your purpose, but null hypothesis testing is over used in these scenarios. Just make three stacked histograms of age by Willingness status. You can also put boxplots under the histograms if you want. This should give you tangible visual information.
  11. hlsmith

    Calculate the sample number by age and gender

    Are you trying to make a representative sample? If so, what is the final purpose using the results? If you try to report stats for these subgroups or make comparisons - you will likely have poor power. Also, are there 60M people in Italy and are you really randomly selecting from all of the...
  12. hlsmith

    Testing linearity assumption in a multiple regression model

    @Buckeye - per my limited knowledge, if the variable was binary, the relationship would be linear since you just connect the point estimates. But if you had ordinal categories, you could put them in a model to look at trend or shape. I would imagine assumptions would be needed related to a...
  13. hlsmith

    Testing linearity assumption in a multiple regression model

    @noetsi I just throw a spline term in the model to see what the relationship looks like. And I take that into consideration along with my context knowledge. Below is a supplemental figure from a recent paper I wrote. I like to look at the df which serves as a pseudo value for how many line...
  14. hlsmith

    Analysis of service delivery

    Good practice. If a person is starting with a low or high income, that will impact what their final income.
  15. hlsmith

    pvalue Model Terms