Tagged Questions

0
votes
0answers
26 views

PROC CORR vs. REG?

Do both my independent and independent variable have to be normally distributed to run a linear regression? My dependent variable is normally distributed, but my independent is not...therefore, ...
3
votes
3answers
303 views

Normality assumption and sample size

I know this is a very debated topic, even on this site, but I still couldn't find an answer to my problem. Recently I am working with large samples (300, 400 and more). For now, I am trying to use ...
0
votes
1answer
133 views

Parametric vs. Nonparametric

I did perform a search for this question (I thought it was bound to be asked), but I haven't found one; hopefully this won't be a duplicate. I'm trying to decide if I should take a course in stats ...
1
vote
1answer
71 views

Nonparametric and parametric parts in semiparametric credit scoring

I am confused about "parametric" and "non-parametric": Our topic is nonparametric estimators for probability of default. So first of all, we consider the generalized linear models, as an example we ...
2
votes
0answers
38 views

Considerations for choosing transformation on small samples?

For a biological investigation, I am taking measurements of a set group of individuals over five points in time. The measurement is always between 0 and 1. Unfortunately, I was unable to measure every ...
1
vote
1answer
314 views

Alternative to 2-way ANOVA when variances are unequal

I'm working on a question on 2-way ANOVA where there are 2 treatments and 1 blocking factor. The residual plots suggest unequal variance. What is another parametric or non-parametric alternative ...
3
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0answers
100 views

Small n: non-parametric of parametric tests?

I am in a situation where I have sample with $n=19$, and the the data are not normally distributed (according to the results of a Kolmogorov-Smirnov test) for all the variables. The data were ...
2
votes
2answers
214 views

How to test group differences when neither parametric nor nonparametric assumptions are met?

Consider following example. We asked 50 men and 50 women one question and they answered on 5 point likert scale (1 is completely disagree and 5 completely agree). Suppose that 50 men responded 20 ...
4
votes
2answers
504 views

Advantage of kernel density estimation over parametric estimation

Is there any particular reason you will choose the kernel density estimation over the parametric estimation? I was learning to fit distribution to my data. This question came to me. My data size is ...
2
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2answers
123 views

Form of $\chi^2$ test

This article uses the following form of the chi-squared test: $\chi^2=\sum\limits_{i}\frac{(m_i-n_i)^2}{m_i+n_i}$ where $m_i$ is the number of counts of bin $i$ in a modeled histogram and $n_i$ the ...
2
votes
0answers
20 views

Tests significative with parametric calculations and non-significative with non-parametric ones! [duplicate]

Possible Duplicate: Comparing smoke and hormones level in two groups of people. Which test? I'm analyzing some data for an article about hormones concentrations and smoking. I was unsure ...
9
votes
3answers
907 views

Is there any statistical test that is parametric and non-parametric?

Is there any statistical test that is parametric and non-parametric? This question was asked by an interview panel. Is it valid question?
3
votes
1answer
3k views

Pairwise comparisons after significant interaction results: parametric or non?

I've run a 2-way ANOVA on growth rate data (grams/day) with the factors of year type (good and poor) and site (A and B). Though the data themselves are non-normal and do not have homogeneous ...
3
votes
2answers
4k views

Advantages and disadvantages of parametric and non-parametric models

I have a large simulated loss data (from catastrophic models developed at my school) to calculate some extreme quantiles. Previously they used non-parametric methods to do this (find the point ...