# Search results

1. ### How would you test this

Are these like the weighing stations?
2. ### Probability Distribution of Cars Sold

Can you post the exact original question in its entirety! Have you covered the Poisson distribution in class?
3. ### 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. ### 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. ### 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. ### Model Fit in AMOS

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

@spunky
8. ### 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. ### Model Fit in AMOS

Remind me what AMOS is? I was thinking it was for time series.
10. ### 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. ### 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. ### 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. ### 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. ### Analysis of service delivery

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

16. ### pvalue Model Terms

@noetsi I simulated this. Boom.
17. ### pvalue Model Terms

Ah you got my attention. Exact p value test. I know Fisher, exact logistic, I think a complete permutation test may be exact. What would it be for multiple linear regression, with continuous vars? Just adding some exact line of code?
18. ### Testing linearity assumption in a multiple regression model

I like to fit a general additive model to look for nonlinear relations.
19. ### Analysis of service delivery

You also should have baseline income right?
20. ### pvalue Model Terms

So if I simulate a bunch of random independent variables and select one as the DV and the rest as IVs, I should expect 1 in 20 will be significant at p value </= 0.05 as the number of terms increases toward infinity, right? By chance, the number of significant terms may be higher than 1\20 at...