Descriptive statistics summarize features of a sample, such as mean and standard deviations, median and quartiles, the maximum and minimum. With multiple variables, may include correlations and crosstabs. Can include visual displays - boxplots, histograms, scatterplots and so on.

learn more… | top users | synonyms

0
votes
0answers
8 views

similarity measure using euclidean distance over descriptive statistics [on hold]

I have multiple data sets ( continuous numeric) of same unit. I want to analyze the similarity measure using euclidean distance between the data sets using the descriptive statistics like min , max , ...
0
votes
0answers
9 views

Studentized range statistic (q*) in Python Scipy [on hold]

I do not mean to spam, but i do not know if different stackexchange communities interface with each other, but i am wondering about the following question ...
0
votes
0answers
17 views

Which statistical tests requires one to know the sampling error?

I would like to know which statistical tests requires one to know the sampling error? I am planning on using an existing public online panel that is representative of the UK population by age, gender ...
0
votes
1answer
24 views

How do I figure out low, high, and median scores?

I am not sure how to make this a problem and solve it. It's statistical data that I am trying to figure out for a paper I'm writing. Basically, I am scoring candidates with 9 questions. Here's an ...
3
votes
3answers
184 views

versus (vs.): how to properly use this word in data analysis

This question is probably more about the English language than statistics, but I have decided to ask it here anyway. When we compare two groups of samples, let's say Treatment vs. Control, and we ...
2
votes
2answers
232 views

Approximate mean from .25, .5, .75 percentiles

If I have median (.5 percentiles), and the .25 and .75 percentiles, what is the best guess of the mean? If the .25 and .75 percentiles are in the middle of a probability mass with weight .5 (.25 on ...
2
votes
1answer
25 views

What statistical method is most appropriate?

I am testing the differences between men and women pertaining to the perceived origin of criminal behavior. I distributed a survey with multiple choice options to pick what each individual thought the ...
3
votes
1answer
40 views

Using a rolling window in time series regression

I am learning about regression. I have done some cross sectional regressions which are fine. I recently did a simple time series regression. So I have a y & x vectors each containing 1000 ...
0
votes
0answers
22 views

Error bars on graph, skewed data, negative standard deviation

I have only had basic stats. I conducted some research where I have four different treatments and results for the data range from 0-6. I don't need any elaborate stats test, I just want to know how I ...
0
votes
3answers
55 views

interpret scatter plot if there is anything to interpret from it

I have an x variable and a y variables. I have done a simple scatter plot. I however don't really know how to interpret (if there is anything to interpret) the plot. I can't find any other similar ...
2
votes
2answers
63 views

Change scores as outcome measurements in clinical trials

I am performing a Meta-Analysis about a mental disease, comparing intervention vs. control groups and try to extract outcome results from published study papers. In some clinical randomised trials ...
0
votes
0answers
9 views

Likert scale analysis , how to analyze it in this case?

I have a questionnaire divided in 4 section. Each section has 5 question ; all of the questions are using the likert scale of 7 points (strongly agree, agree..etc..) I want to compare the 4 ...
0
votes
1answer
20 views

interpreting NMDS ordinations that show both samples and species

I am using the vegan package in R to plot non-metric multidimensional scaling (NMDS) ordinations. I am using this package because of its compatibility with common ...
3
votes
1answer
33 views

MSPE formula - is the number of variables not important?

The formula I usually see for MSE is: $$\mathrm{MSE} = \frac{\sum\limits_{t=1}^T e_i^2}{n-k-1},$$ Whereas for MSPE it is usually: $$\mathrm{MSPE} = \frac{\sum\limits_{t=T}^{T+P} e_i^2}{P}.$$ So ...
0
votes
0answers
20 views

Deducing an approximation to the Gini coefficient

Assuming we do not know the Lorenz curve function, If $(X_k, Y_k)$ are the known points on the Lorenz curve, with the $X_k$ indexed in increasing order $(X_{k – 1} < X_k)$, so that: $X_k$ is the ...
19
votes
4answers
976 views

Why shouldn't the denominator of the covariance estimator be n-2 rather than n-1?

The denominator of the (unbiased) variance estimator is $n-1$ as there are $n$ observations and only one parameter is being estimated. $$ ...
2
votes
2answers
43 views

Conceptual understanding of standard deviation

I always understood standard deviation to be the average distance of the observations from the mean. But when I generated a standard normal distribution N(0,1) with n = 1,000,000 in Excel, and took ...
0
votes
0answers
14 views

Month Wise Descriptive Statistics

I have a Large Data Set of prices, Spanning across 15 years, I need to find out descriptive statistics? The Problem is there is a Trend Element in the Data, hence I need to break up the descriptive ...
0
votes
1answer
40 views
0
votes
1answer
34 views

Similarity between two samples (2D matrices)

I have two matrices: A= 4000x78 where 78 is the dimension of features and 4000 is the number of samples. B= 1000x78 where 78 is the dimension of features and 1000 is the number of samples again. ...
0
votes
3answers
118 views

What is the difference between variable and random variable?

I know that "variable" means "values which vary." In a simple linear regression model : $$Y=\beta_0+\beta_1X+\epsilon$$ $X$ is variable that is the values of $X$ vary. Why is $X$ not a random ...
2
votes
1answer
108 views

QQ plot in Python

I generated a qq plot using the following code. I know that qq plot is used to check whether the data is distributed normally or not. My question is what do the x and y axis labels indicate in qq plot ...
0
votes
0answers
21 views

Frequency polygon area

If I have a histogram with bins equal width, then the area of the histogram is the same as the area of the frequency polygon. What about if we have an histogram with bins of different width? I think ...
0
votes
0answers
11 views

Creating A weighted Scorecard using Stats

Im new to forum and have tried reading some articles to solve my problem but had trouble understanding some of it and others might not have been completely relevant. Below I will outline my problem ...
0
votes
0answers
20 views

How to identify items answered differently by some factors such as male vs. female?

I want to do something like this: Variable: students (undergraduate, master students, and PhD students) Research instrument: XXXX (20 items) Reporting: The ANOVA analysis suggested that there is no ...
1
vote
0answers
18 views

Calculating the highest of overlapping sets

My data set looks like the following: I have information about a large number of devices. For each device, I also have the data consumed by an application per day. Note however, all the devices ...
0
votes
0answers
12 views

What are the conditions for Pooling Samples

I am trying to understand when it is ok to pool samples. The problem i have is that with more then two samples, it is possible that pairwise comparison of the samples could lead to the following ...
-3
votes
1answer
92 views

Calculating mean and variance of normal distribution restricted to interval

If one set a lower and an upper limit on the normal density, is it statistically valid to calculate the mean and Standard deviation of that normal variate. If yes, how can we do that in R? In a more ...
0
votes
0answers
26 views

LDA with three variabilities

In a classical linear discriminant analysis (LDA), we usually have only two variabilities to handle (the between classes and the between individual variability). Usually LDA is used to maxmize the ...
0
votes
1answer
42 views

What analysis can I do when I have different design and I would like to analyse together?

I study the relationships between plant community (forest restoration) and soil properties. My experiment is 15 years old, and I have a block design with five treatments and three replicates. I have ...
2
votes
1answer
60 views

How to calculate the Standard Deviation of a set of Percentages

I would like to know how to calculate the standard deviation (SD) of a set of percentages. Let me explain better. Some students performed a test and I counted the number of right answers for each ...
0
votes
0answers
47 views

What summary statistics can be applied to the results from a multiple choice question?

I have a list of answers given for a multiple choice question. For multiple choice I mean that from a set of possible answers given, more than one can be chosen. For other answers with single choice I ...
0
votes
1answer
103 views

How to caculate power analysis in a descriptive study

Hi I'm currently doing a dissertation, its a descriptive quantitative study. The method of data collection is a questionnaire scaled by a 10 point Likert scale. To calculate the sample population ...
0
votes
0answers
41 views

Analysis of Descriptive Statistics

I'm trying to make an assessment of these figures, with the aim of using them for multivariate regression. I'm struggling and so far all I have is: "With the lowest skew, kurtosis closest to zero ...
0
votes
1answer
23 views

key points for unofficial stats-101 for service guys

Background: In my previous job there was an official "stats 101" course. It was brilliant. It gave all the production and engineering folks a shared vocabulary, and provided a decent foundation to ...
0
votes
0answers
18 views

About GEE and how to do it

I have read this article many times but could not figure out how they did GEE and revealed a percentage increase. I have similar data set, restructured for repeated measures. But cannot figure out ...
0
votes
1answer
15 views

Comparing means

I have 3 continuous variables: fixation index for known words, unknown words and familiar words. There seems to be a difference between them but I am confused how to compare means in a significance ...
2
votes
0answers
41 views

Very large dataset with more than 2000 variables descriptive statistics in multicore [closed]

I deal with very large datasets everyday with millions of rows and thousands of columns. I can sample down to do descriptive statistics, but the people i work with here do not believe in sampling ...
0
votes
0answers
21 views

Name of two dimensional-space — feature-space

I have 2 features and want to perform some functions independently on them in two-dimensions. So basically I have 2 two-dimension spaces. How can I name them? Should they be called as feature-space 1 ...
0
votes
0answers
14 views

Increase ratio pre test and post test

I have a pre test and post test and for each question (15 questions in total) students get 1,2 or zero points. There is an increase in post test but I want to know which score value increased more ...
0
votes
0answers
30 views

Appropriate Statistical test for Analysis [duplicate]

I have built and tested a computer application, which involved two participant groups (Group-A with existing knowledge of databases and Group-B without knowledge of databases). I was required to ...
1
vote
1answer
27 views

Relate $Var(y)$ with $Var(y)_{(i)}$

How can I relate $Var(y)$ with $Var(y)_{(i)}$ where $Var(y)_{(i)}$ is de variance of the data with the ith item removed. It is necesary first relate $\bar{y}$ with $\bar{y}_{(i)}$ and it complicates ...
1
vote
1answer
24 views

What's the meaning of 'statistical break'? And how to calculate it?

I am reading a paper named "EPRI-GTC Overhead Electric Transmission Line Siting Methodology", and in this paper the author uses "the first statistical break in its histogram" to determine the corridor ...
2
votes
1answer
192 views

Sampling distribution, mean, standard deviation of finite discrete uniform population

Given positive integers $a$ and $b$ ($b \leq a$), where $c$ is the set of all combinations of $a$ digit binary numbers, with $b$ 1's, and where $c_1$ is least significant bit, and $c_a$ is most ...
1
vote
0answers
70 views

How to describe/define tail of a distribution

I have a histogram showing a distribution with a long tail, and I would like to come up with a definition (in words) for the points fall inside the "tail", not based on quantile or standard deviation, ...
1
vote
0answers
45 views

SPSS: descriptives in repeated measures

This is a question that has been bothering me for a long time, and until now I haven't been able to come up with a decent solution. Imagine you do a straightforward repeated measures analysis in SPSS ...
2
votes
1answer
80 views

Problem expressing full conditionals

I have this problem, $Y_{i}$~Gamma($\alpha$,$\beta$) 1...N $\alpha$~Exp($\lambda$) $\beta$~Exp($\lambda$) $\lambda$=0.001,Find the full conditionals. I have done the following: ...
2
votes
3answers
64 views

What is the term for E[x*y']

I know this is probably a very simple question, but I recall learning that for 2 random vectors, x & y, with mean mx & my, E[(x-mx)(y-my)'] is the covariance & E[xy'] is the correlation ...
1
vote
2answers
57 views

Likert Scale 3 2 1 0 1 2 3 possible?

In my questionnaire I want to ask people to score on a dimensional Likert-type scale their attitude toward a specific target group. E.g. People with .... are stupid.... intelligent. I want to use ...
1
vote
0answers
14 views

Looking for a package to symbolically manipulate statistical expressions

I'm looking for a package that allows to manipulate statistical expressions symbolically, similar to how one can simplify, expand, factor, etc. with Matlab, Mathematica or SAGE. Using rules such as ...