Questions tagged [parametric]
The parametric tag has no usage guidance.
42
questions
19
votes
3
answers
5k
views
Why are parametric tests more powerful than non-parametric tests?
I'd like to understand why parametric tests are more powerful than their non-parametric alternatives. Is the word choice of "power" the same as statistical power? As I understand it, power ...
- 1,653
13
votes
4
answers
958
views
Example of a parametric test with no normality assumptions?
I read an article saying that "all parametric tests make an assumption of normality", which I know to be incorrect, since technically a parametric test could be done for any distribution, ...
- 139
11
votes
2
answers
3k
views
When do we have nuisance parameters?
From Wikipedia:
a nuisance parameter is any parameter which is not of immediate interest but which must be accounted for in the analysis of those parameters which are of interest.
Suppose originally ...
- 19.6k
3
votes
2
answers
180
views
How to handle assumptions of statistical tests?
Does any definitive work exist, e.g. a review, a book chapter, or a book, on the advantages and disadvantages of existing approaches? Is there a consensus on which approach is the right one?
I have ...
- 199
3
votes
1
answer
141
views
Are there any parametric machine learnig models that can represent non-linear behaviour between a predictor and a targe variable?
Some basic models, like multiple linear regression (MLR), are parametric but usually limited to linear interactions between X and y. Other models can represent non-linear interactions between X and y, ...
- 317
3
votes
1
answer
131
views
If I have a very small n for one group and a very large number of features, should I choose a parametric or a non-parametric test?
I have a dataset that contains human metabolite concetration in a fluid. One group has about 12 samples, while another only has 5. My question is if I can assume normality for this data and do ANOVA/t-...
3
votes
1
answer
145
views
How to parameterize covariates in parametric time to event model (lognormal distribution)
I have a parametric time to event model for survival data and I found that a lognormal distribution has the lowest objective function value for a base model. Below is the hazard function for the ...
- 33
2
votes
4
answers
469
views
I want to show by simulation that the Wilcoxon test is more robust than the Student test for non-normally distributed data
I want to test by simulation that the Wilcoxon test is more robust than the Student test for non-normally distributed data.
For example, I'm testing the ...
- 909
2
votes
1
answer
421
views
GAM - parametric coefficients - what is mgcViz::pterm() actually plotting?
I built a GAM with two categorical variables and two smooth terms, following this structure:
...
- 637
2
votes
1
answer
54
views
Are there families of known parametric copulas for non-standard marginal normal distributions?
I know that a family of Gaussian copulas generates a standard bivariate normal distribution if and only if the marginal ones are standard normal. This characterizes the Gaussian copulas, where I have ...
- 21
2
votes
1
answer
127
views
Fisher Z transformation still not normal
I have 18 different groups that I need to compare. I used the raw values from a neuroimaging file to represent synchronization between two brain regions (which ranged from 0 to 1) and Fisher Z ...
- 21
2
votes
1
answer
741
views
Is Kernel-Regression parametric or non-parametric?
As the title says, is kernel regression a parametric or non-parametric method, and how can this be motivated/explained?
- 35
2
votes
2
answers
478
views
Which test should I use to compare a normal distribution sample with skewed distribution sample?
I have two groups : Infection group (n=26) and healthy control group (n=127).
The aim is to see if there is a difference in the mean of T cells absolute count* values between the two groups.
Ho= the ...
- 21
2
votes
3
answers
479
views
When is a hypothesis test appropriate? [closed]
For example, when would a hypothesis test bed used?
- 51
2
votes
0
answers
24
views
Is there a statistical test for five groups with averages ONLY?
The data I collected was measuring plant shoot masses and these were extremely small, so I could only find the total mass of the shoots from 30 plants. Hence, I only have the mean and none of the ...
user387381