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.

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Obtaining adjusted proportions with logistic regression

Can I obtain adjusted proportions of a binary variable by using logistic regression? I have a binary variable (normal/abnormal), which I'd like to obtain adjusted prevalence for (i.e the proportion ...
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20 views

Inferential statistical tests and descriptive tests [closed]

I am doing a retrospective study evaluating medication use in 500 TB patients in a hospital. What type of inferential statistical tests and descriptive tests can I use?
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1answer
30 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 ...
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1answer
22 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 ...
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26 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 ...
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1answer
28 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 ...
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29 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 ...
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1answer
18 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 ...
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16 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 ...
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1answer
14 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 ...
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21 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 ...
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10 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 ...
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13 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 ...
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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 ...
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1answer
25 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 ...
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1answer
23 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 ...
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1answer
124 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 ...
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0answers
47 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, ...
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0answers
29 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 ...
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1answer
79 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: ...
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3answers
63 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 ...
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2answers
50 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 ...
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0answers
13 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 ...
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1answer
48 views

What statistical analysis should I use for my study?

In my psych class we were testing to see if groups of men or groups of women would be more helpful in an emergency situation (we are testing for the bystander effect), and we are testing to see if ...
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15 views

Is it reasonable to utilize z-scores

I have empirical observations to be compared with discrete distributions of random values (generated according to random models). The shape of my random distributions is not normal(according to ...
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18 views

When is appropriate to combine two treatment groups from one study into a composite whole for a meta-analysis?

The treatment groups I would like to combine appear to be virtually the same, at least by generic label for each group, e.g., groups with the same treatment but implemented at different sites or ...
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17 views

Comparing two differences in proportions

Based on cross-sectional data from hospitals, I have two 2x2 tables. One 2x2 table is for treatment A. The proportion of males with a binary outcome is 0.2 and females is 0.3, and the difference in ...
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9 views

What does the standard error of difference 0 mean in form of general statement and then how to proceed further?

I am conducting analysis of data collected from same sample about present state and there expectations on different variables of same service. but t-test cant be conducted on 8 out of 12 variables ...
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1answer
63 views

Calculating standard error after a log-transform

Consider a random set of numbers that are normally distributed: x <- rnorm(n=1000, mean=10) We'd like to know the mean and the standard error on the mean so ...
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0answers
24 views

the approach of performing correlation analysis between categorical and numerical

What are the approaches to perform correlation analysis for the following pairs: ...
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0answers
28 views

Statistical methods in healthcare management [closed]

I am going to contribute to a workshop on "statistical tools for healthcare managers". Any suggestions where I can get some references specific to this area? and data sets?
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17 views

Statistics: Eliminating the effect of one parameter

a quick statistics question. Consider having a conveyor band inside a black box. A test-object is pulled through the black box at different(known) speeds whilst gathering sensor data (temperature ...
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2answers
44 views

Scales of Measurement

when we use the term " scales of measurement", what do we mean by scale by Measurement ? As far i know, measurement denotes "a value" and scale denotes "the unit" of the value. So if i say, ...
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1answer
22 views

How to find three probabilities with two different values or ratings?

I would like to know how to find three probabilities of two values.... Specifically...I want to know the three soccer venues (HOME DRAW AWAY) proabilities with two ratings... Example: I have two ...
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4answers
224 views

Is there a measure of 'evenness' of spread?

I looked up on the web, but couldn't find anything helpful. I'm basically looking for a way to measure how 'evenly' a value is distributed. As in, an 'evenly' distributed distribution like X: and ...
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1answer
30 views

Can I use this equation for prediction?

I've got a question. Below you see a graph which shows the regression equation between construction activities in the private sector (X axis) in £bn and the total amount of all construction activities ...
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48 views

Is there any use of having dual error bars in bar charts to show both descriptive and inferential statistics?

I would like to display information both about the distribution of the population and the certainty in the measurements in the same plot. Would there be any use of having dual error bars in a barchart ...
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18 views

Decriptive statistics for a large amount of times series

I have 1,000 individual company time series of a variable, say X, observed 500 times (weekly observations). I would like to describe how this variable behaves. A graphic presentation of each time ...
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39 views

Should a BoxCox transformation to normalize the skewness of data be applied to all the predictors?

If there are few predictors that are highly skewed among a larger set of predictors in case of a linear regression problem, should a BoxCox transformation be applied to only these few predictors or ...
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1answer
15 views

Correcting multiple marginals in a subsample of a survey

My question in short: How to assign weights to a subsample of a survey in order to fit multiple features simultaneously to their original marginals? ...and now the details: I have some data set X of ...
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0answers
47 views

Should descriptive statistics on percentages data be weighted?

I'm trying to put together descriptive statistics for a set of differently sized groups of students. For each group of students, let's say I know the # of students who are left handed. I'd like to ...
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1answer
49 views

Linear model decomposition

Is is possible to decompose fitted linear model? What I mean by that: I have parameters of fitted linear model as following: y=2.3a-1.23b+1.65c+1.76d Now I have ...
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43 views

Using t-test for feature selection after z-scoring data?

Suppose I have a high-dimensional dataset, and a binary classification problem. I want to use the two-sample t-test for feature selection. If the data has been normalized by z-scoring (so it has zero ...
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1answer
24 views

Best statistical method to show different performance week over week

I am trying to get best statical method to show performance of accumulative revenue by customer compare week over week. Currently I have about over 100 customer charts compare by hour from same day ...
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0answers
34 views

Statistical nomenclature: what family does “head” and “tail” - in the sense of data runs belong

If I look at mean, variance, skew and kurtosis they are nth moments. If I look at percentiles, quartiles, and medians they are order statistics. Both work together to make a textbook summary. The ...
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2answers
67 views
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regarding the statistics to test the impact of some subset values on a given variable

For a given variable, there is a set of values. We know that these values can belong to different clusters. For instance, a lot of values center around a small value while other values center around a ...
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1answer
25 views

Matching two power signals for similarity

Below are the images of two signals that i plotted. Both the signals are from fridge belonging to different houses. Visually looking at the plot i can tell that these plots belong to fridge as they ...
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0answers
39 views

questions on characterizing a variable into ordered, categorical or continuous

When building the regression models, some independent variables are of the following type x={1, 2, -100.1, 200.1, 300, 0, 0, 0, 0, 4000} If there exists an ...
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2answers
171 views

What are some good examples of exploratory data analysis today?

Are there some papers published which illustrate EDA used to tackle substantial data problems? I am particularly looking for actual (current) data examples, where plots have been made and statistics ...