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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33 views

R - Same Density but different QQ-Plot?

I have data variable corresponding to quotation amount and I want to find which statistic law this variable follow if there is one. It seems that the ...
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1answer
24 views

Dealing with variable certainty in categorical data

I have a question regarding statistical analyses for categorical variables. Without complicating it, I would like to know how you can deal with uncertain categorical data. That is, categorical data ...
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14 views

Running multivariate tests on ecological data

I have been looking at how the shape and structure of corals affect the types of organism that lives upon them, but could do with a little help on the stats. I haven't really used any statistics for a ...
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17 views

Descriptive statistics in my native language in R [migrated]

Regardless of R! variables: Sys.setlocale("LC_MESSAGES", 'pl_PL.UTF-8') Sys.setenv(LANG = "pl_PL.UTF-8") when I use function such as summary, output is given in ...
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2answers
106 views

Is there a non-parametric Coefficient of Variation?

I was reading a paper where the author mentions: "The coefficient of variation is primarily a descriptive statistic, but it is amenable to statistical inferences such as null hypothesis testing or ...
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1answer
26 views

what is the intuition behind the SRSWOR formula?

I earlier asked about Slovin's Formula (http://math.stackexchange.com/questions/1410492/what-is-the-intuition-behind-slovins-formula), and learned shortly thereafter that it was derived from this ...
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64 views

How to detect different social groups in a small questionnaire dataset?

I work with a very small questionnaire dataset, in which perception of 10 respondents to the size of, say, an unseen population is quantified: The population is divided into eight sub-populations, and ...
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15 views

Comparing categorical and numerical results simultaneously

This question is in regards to options for analysing a dataset. I have a dataset where we have 23 video clips that have been treated using three different algorithms to change how each clips looks. ...
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29 views

Is this analysis sufficient, have I overlooked important statistical tools/terms [closed]

I'm doing a master thesis project, looking for patterns between two datasets. I have not had any statistical courses or similar. So I'm in doubt if I'm on the right track. Any comments or tips/tricks ...
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12 views

measure of multivariate skewness

I am looking for a generalization of Pearson's or the Yule-Kendall's skewness measures, from univariate to multivariate data. If not a proper generalization, any other measure sensitive to the ...
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0answers
19 views

Coefficient of variation for non-normal populations?

If samples of prices of different items are taken and I want to compare the variation in prices between the items can I simply use the coefficient of variation to do so? Or, in order to do this ...
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17 views

How z-score normalization is best strategy for data normalization in classification task

I have read in many technical articles that z-score normalization is best way of normalizing data in classification task. But, it subtracts mean of data from every sample in data. So, data of two ...
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1answer
53 views

Is there a “smooth” version of a median of a data set?

So I'm thinking about how one would compare sizes of past civilizations in terms of population size and territory, and imagining that the distributions are basically continuous variables. I know ...
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2answers
35 views

How to check if a data set can be modelled by a normal distribution

I have a set of velocity data (37 data points) and I want to know how to check if the data can be modelled with a normal distribution. From a guide on youtube I have calculated the CDF, expected ...
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0answers
14 views

Narrowing sample

Data was collected over a period of 20 years. Samples of population were systematic with random generated start (between 1 and 10). Each sample plot was measured by plant type and density. There were ...
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1answer
41 views

How to show that outliers come disproportionately often from a particular group? (context: bibliometrics)

I got the following quandary and wondering if you have any thoughts on how to show/test it. I work with peer review data and notice that many of the most highly cited articles in my data were "first ...
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1answer
33 views

How do I normalize a vector of numbers so they are between 0 and 1? [duplicate]

I have a vector of numbers (both positive and negative). How can I normalize it so the values of the normalized vector will be between 0 and 1?
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18 views

Which statistics result can be derived from this data?

I have 2 information sheets. 1st one is monthly period data on x-axis(2011 Jan to 2014 December) and # of lung cancer patients divided by population on that period multiplied by 100 on y axis. ...
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1answer
32 views

What is the standard way to distinguish the errors associated with sampling and measurement in statistics?

This is probably a very basic, yet not easy, question in applied science. I was just wondering, what are usually the standard ways to deal with it? Any pointers to further references are greatly ...
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36 views

Sample size when using GPS-trackers to analyze movement of reindeers

If one were to try and analyze the movement of ~2 500 reindeers before and after a (man-made) change in landscape have occured. Specifically how spread out the herd is, both as a whole and if there ...
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7 views

Statistic way to find a threshold for NGrams occurrence

I got a vector of Bi-Grams with their occurrences, and I have to calculate tri-grams from the most occurrent bi-grams. Therefore I need to find a statistic way to find a threshold of big-grams ...
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0answers
5 views

Find the expected frequency of some state in a state sequence of length N given a transition matrix M

I can represent stochastically-articulated sequences of states using a transition matrix M where a given entry in cell (i,j) corresponds to the probability of state j given that the current (or, most ...
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2answers
70 views

How measuring the proportion of object in several classes?

I have 4 classes and I want to classify objects in each class. I have an arbitrary number of objects indexed from $1$ to $n$. My problem is, when $n$ varies, the proportion can change a lot. For ...
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23 views

Cronbach's alpha, When to use it

I am a bit confused about the use of Cronbach Alpha. I have a questionnaire I administered to 20 respondents. I have gotten the data back from the survey. I am told I need to do an Internal ...
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29 views

Calculation of median: Why are means of ranks not used for it?

in order to calculate the median, I have to sort the data in a ascending/descending order. Each value gets a rank so that I can (for uneven samples) look up the value that rank X = (n + 1)/2 has, ...
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20 views

Regression not sure

My early research shows that after giving voice therapy children improve their phonetic production- faster reaction times ( I had 10 participants who named 20 items pre and 20 post therapy). However, ...
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1answer
41 views

best arima model in R

I'm new to R. I'm trying to fit an ARIMA model to a large time series. The best model found with auto.arima is ARIMA(0,0,5). The residuals plotted with tsdisplay are looking like below. Can someone ...
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1answer
57 views

Explanation of the different variable types in statistics?

One thing that has always tripped me up when trying to learn new methods in statistics is understanding what type of features/variables can this method be applied to. The variable types that ...
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0answers
25 views

Which test(s) to use?

I’m having a dataset that needs to be analyzed but I’m a bit worried about picking the appropriate test(s). It’s been a while since I last really used statistics and SPSS. Therefore I would kindly ...
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36 views

1 IV, two levels; 2 DVs (one post-test only, one pre-test & post-test). Have some ideas but unsure. Cliche question but:What stats test to use?

I'm working on a proposal and trying to get my stats tests right. Been doing some reading and while I'm beginning to get a better grasp of things, I'm still a little puzzled as to what stats test to ...
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1answer
87 views

Correlation between a percentage and a real number

I have two datasets, one containing the percentage of people with flu and one which has the number of searches for Tea-recipes in google. Problem is, I get different results when i choose to include ...
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4answers
994 views

Percentile vs quantile vs quartile

What is the difference between the three terms below? percentile quantile quartile
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0answers
17 views

Standardizing IQR

Suppose I have a data set like the following Q1 Median Q3 IQR 10 20 30 20 15 20 35 20 100 200 300 200 I don't have the actual data ...
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33 views

How should population sample characteristics be presented for a small sample size?

I'm performing a clinical trial and have enrolled 16 patients, of which 3 had to be excluded. I suppose it would be relevant to present some characteristics of the included patients, e.g. age, weight, ...
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26 views

Finding descriptive statistics on particular days on the time series

I got a time series of returns for the last 15 years. I would like to extract the descriptive statistics on last Thursday of every month. Suppose, if I add a filter for last Thursday of every month ...
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9 views

Relative measure of a questionnare

I have a psychological questionnaire which deals with people's satisfaction from life. The questionnaire is build from several questions, each has a weight (how many points it is "worth"). The total ...
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34 views

Should I normalize my variables for a descriptive logistic regression?

I'm running a logistic regression in order to descriptively analyze the relationship between my independent and dependent variables. As I understand it, it's not mathematically necessary to normalize ...
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54 views

Combining multiple metrics to provide comparisons/ranking of k objects [Question and Reference Request]

Collecting $n$ metrics about $k$ objects Suppose I collect $n$ metrics about $k$ objects. I am looking into valid ways to compare the $k$ objects so they can be "ranked". I think this may be ...
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1answer
48 views

Standard deviation of a casino's profit

For the following question, I've determined the mean to be \$0.20, but how do I determine the standard deviation? A slot machine at a casino pays out an average of \$0.9, with a standard ...
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1answer
44 views

Why pnorm function and sum of dnorm function differs for same input?

Data is height of men in 'inches'. Mean is 70. SD is 3.3 I wanted to compute the probability of men whose height is in between 69 inches and 74 inches. The following methods gave me different ...
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3answers
58 views

Non-normal univariate distribution — how to define “low” to “high” subsets of values?

Sorry for the dumb question: it's been a million years since I took basic stats. I have a set of 48, non-normally distributed values ranging from 1 to 100. I'd like to be able to apply a (valid) ...
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0answers
26 views

suitable statistics to replace box plot [closed]

I am applying few classification methods on a set of images. Currently, I have experimental results in box-plots and want some statistical method to report them in my dissertation. Problem ...
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0answers
29 views

Issues with derivative of a copula density

Suppose I have a bivariate copula density with marginals $F(X)$ ($F(X)$ is normal with parameters $\mu_1$, $\sigma_1^2$) and $G(Y)$ ($G(Y)$ is normal with parameters $\mu_2$ and $\sigma_2^2$). I want ...
2
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0answers
51 views

Estimating probability distribution function of data stream

Although a similar question exists, I couldn't find my answer. I'm not a statistician hence please neglect if some terminologies aren't correct and let me know if I am interpreting something wrong. ...
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0answers
30 views

Can you calculate descriptive statistics (SD, SE particularly) from percentages and ratios?

I'm a cell biologist and a lot of my data is expressed as a fraction (percentage) of the total number of cells in a single experiment in a number of separate categories (generally 5 or so). The number ...
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1answer
32 views

What's my population? Is this Descriptive or Inferential?

I have a list of employees at a company. I want to show some comparison of some demographics (say, %female) of those who have left the company and those who have stayed with the company. However, I ...
4
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1answer
227 views

Is the following dataset possible?

"Is it possible to create a data set where $\bar{x}=30.0$, range $R=10$ (meaning the max-min=10), and variance $s^2=40.0$?" I feel sort of dumb asking this question, but I'm not quite sure I'm on the ...
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0answers
50 views

Efficient statistical test to compare two multivariate distributions

I am looking for a test to assert the "equality" of two multivariate discrete distributions, $\mathbf{A}=\{A_1,\dots,A_k\}$ and $\mathbf{B}=\{B_1,\dots,B_k\}$ for which I do observe two samples ...
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19 views

Forecasting Prediction Accuracy

Out of 4 error paramters which one is best for evaluating prediction accuracy? Average error Mean absolute error Mean squared error Mean absolute % error why?
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21 views

What is the best way to group countries for graphing world crime statistics?

I am currently working on a project where I have chosen to analyse the frequency of terrorist attacks and their impacts using the global terrorism database (dataset available here: ...