Linked Questions

59
votes
14answers
8k views

Why would parametric statistics ever be preferred over nonparametric?

Can someone explain to me why would anyone choose a parametric over a nonparametric statistical method for hypothesis testing or regression analysis? In my mind, it's like going for rafting and ...
12
votes
4answers
57k views

Should the mean be used when data are skewed?

Often introductory applied statistics texts distinguish the mean from the median (often in the the context of descriptive statistics and motivating the summarization of central tendency using the mean,...
8
votes
4answers
3k views

Zero-sum property of the difference between the data and the mean

I am new in statistical studies and on this site and I came across the "zero-sum property" in my book regarding the mean. It seems to be straight forward but I still can't understand the notion of it. ...
6
votes
3answers
5k views

Sensitivity of the mean to outliers

Is the mean sensitive to the presence of outliers? I initially thought it wasn't, because a small amount of observations shouldn't have much impact, but was told that since those observations have ...
3
votes
3answers
2k views

If the mean and median underestimate the true central tendency, why use them?

In skewed distributions, both the mean and the median can easily underestimate or overestimate the true central tendency. For example, have a look at this violin plot: The median is shown here in red....
7
votes
5answers
361 views

Why care so much about expected utility?

I have a naive question about decision theory. We calculate the probabilities of various outcomes assuming particular decisions and assign utilities or costs to each outcome. We find the optimal ...
3
votes
2answers
1k views

Parametric vs nonparametric methods [duplicate]

Are non-parametric methods preferable to parametric methods since the former do not force the model to have a parametric structure?
0
votes
1answer
828 views

Sum of squared errors [duplicate]

Why do we use SSE (the sum of squared errors) in calculations. Why do not we use the sum of errors? Could you explain please?
0
votes
1answer
281 views

using Mean or Median [duplicate]

Wondering if any general guidelines whether using Mean or Median is better to represent the statistics of underlying data? I think using Median is always better, especially better when standard ...
1
vote
1answer
325 views

Why don't dispersions like median deviation and mode deviation exists on the lines of mean deviation?

Or to say in the formula MD=$\frac{1}{N}\sum_{i=1}^{N}|x_i-\overline{x}|$ why can't we have median or mode instead of mean($\overline{x}$) and as a result speak about additional possible measures of ...
3
votes
0answers
1k views

Mean, median, or mode of skewed posterior?

I'm estimating an ICC from 2 and 3-level hierarchical models using rstanarm. The simplest models are: y ~ (1|group) or ...
0
votes
1answer
352 views

Bayesian smoothing using Dirichlet prior : why not MAP?

I am reading about smoothing methods for language model ( I am working on unigram model). If you are not familiar with unigram model, it is closely related to multinomial distribution (with the ...
3
votes
1answer
264 views

use and misuse of Winsorization

I am doing research on Winsorization (and trimming), which has been broadly applied in many fields, but I think many researchers didn't do it in a "rigorous" way. Or maybe even worse, they misuse it. ...