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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What is the most effective way to get a baseline rating prediction from netflix rating data?

I am doing an assignment where I am working with some of the Netflix Challenge data. I have a database that maps movie ids to customer ratings of that movie and a database of customers mapped to ...
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1answer
45 views

Which of the several measures of d-statistics is better for a meta-analysis of effect-sizes?

Several measures including Cohen's d are available for computing d-statistics. It is difficult to choose one of them for a meta-analysis? Are there any guidelines ?
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11 views

How to measure the impact of a product on the global revenue?

We have products daily revenue and when each product started being sold by the company. We also have different break-down of product revenue by location, store, sales person, etc. We need to measure ...
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1answer
18 views

Why confidence interval is important when point estimator is close to zero? [duplicate]

When the point estimator is relatively small numbers, a confidence interval is likely to contain zero, be fairly wide and include both positive and negative values. Basically, when CI contains zero ...
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1answer
17 views

What is the relationship between median disease free survival and median follow-up distribution?

I created a Kaplain Meier disease free survival curve with the following statistics (in months): ...
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24 views

clustering or segmenting the data

A defined set of products is distributed across different shops randomly across different regions in the world. I would like to know about the statistical techniques that i can use to do the ...
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1answer
44 views

Intuition behind pearson correlation, co-variance and cosine similarity

In this post, the best answer gives excellent mathmetical explanation among pearson correlation, co-variance and cosine similarity. Where I quote here ($\mathbf A $ is the data matrix). If you ...
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24 views

probability of a single value belonging to a population

what is the appropriate approach to estimate the probability of a single sample belonging to a population? Specifically, I am calculating a particular value from the comparison of two time series. ...
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19 views

How can I calculate the average age of survey respondents? [duplicate]

A question in my survey asks about the age of respondents. Respondents are asked to choose one of these four ranges: 18-29 30-49 50-64 65 and over How can I calculate the average age of respondents?
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1answer
46 views

How to standarise percent values 0 - 100%

I'm working on dataset that contains a variable from 0 to 1 (0 - 100%). Distribution of the variable differs depending on the context (defined by another variable). Depending on the context the ...
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10 views

What are some of the more popular variable transformations and why/when are they used (to handle what types of distribution problems)?

Like the title states, I'm interested in learning about the more popular data transformation techniques. I know the internet is abound in this information, but I'd like to hear from those working ...
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13 views

usage of adjbox() in R [duplicate]

Anyone here who could describe the usage of adjbox()? Is it used for very skewed distributions to have a more generous range like the boxplot? What is the formula like mean+1.5*IQR in boxplots? Is it ...
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13 views

chisquare outlier test assumptions

what are the assumptions of the chisquare outlier test? ( in R: chisq.out.test()) Is it only applicable if the data follow a certain Distribution? What is the idea of ist Definition of outliers? ...
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16 views

level of variable?

I was looking at this What does the level of a variable mean? I can only think of categorical variables with 2 values, like gender. Is there continuous variables with only 2 levels?
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21 views

Appropriate testing for outliers

I want to perform an outlier-test for my data. The distribution of the data looks like a hyperbola (there are many values near 0, all values are >0). Sample size of data is 5000. I want to find an ...
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12 views

PDF from standard deviations plot

I must consider a plot like this that shows the bounds on $x$ (in this case $\sin^2\theta_{12}$), in terms of standard deviations $N\sigma$ from the best fit. How can I extract the PDF of the $x$ ...
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16 views

statistical tolerance

My request is: I have data (sums of money) and someone calculated tolerance limits for the data. I want to validate these tolerance limits with statistical methods/arguments. Does anyone know ...
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6 views

Responses to likert scale - how do I work out if the same participants are saying don't know

I have a 10 questions whose responses are on the likert scale (agree, neither agree nor disagree, disagree, and don't know). I want to work out whether those that selected 'don't know' across all the ...
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7 views

to constrain a parameter estimate to obtain unique estimates in R LAVAAN for CFA

I need urgent help, I need the script or command to constrain a parameter estimate to obtain unique estimates in R LAVAAN for CFA. Like If Social Influence got 4 items in a model and I want to put a ...
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1answer
34 views

Are the distances of the kNN i.i.d?

Imagine the set of i.i.d observations $D = \{x_i\}_{i=1}^N \subset X^n$. Let the distance function $d \colon X^n \times X^n \rightarrow \mathbb{R}$ be used to find the $k$ nearest neighbors to the ...
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14 views

Finding Power Function for a LRT test

I am trying to solve the following problem: Let $X_1, . . . , X_n$ be a random sample from the $Uniform(θ, θ + 1)$ distribution. Derive the power function for the LRT for $H_0 : θ = θ_0\ vs.\ ...
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9 views

Best metric for differences between shares

I am looking for a simple metric to measure the differences in expenditure shares on commodities which were calculated differently. Thus, there are two scenarios, both of which report expenditure ...
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15 views

Unsure about what statistical test to carry out

I have a blood count data with a sample size of over 3000. I am dealing with these variables only: age, sex and WBC:Platelet(ratio). I am using SPSS and already done some descriptive statistical ...
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28 views

How to detect the inflection point or the change point in a Q-Q plot?

Following are two QQplot. Both of them has an inflection point, which can be found easily by human eyes. However, I'm not sure whether there is a robust statistics way to find it.. Does anyone have ...
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1answer
48 views

How to properly display changes in percentages over time?

Our company is developing self-learning software that extracts data from documents and enters it automatically into text-fields in some other software, on behalf of the user. These suggestions aren't ...
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1answer
15 views

what method to test percentage against population percentage?

I have population of 6 regions, and also customers from these regions. What is the best way to test if the percentages of customers from these regions are about the same as the population percentages?...
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141 views

How to extract distribution information from descriptive statistics?

In my thesis, I am trying to perform a Monte Carlo simulation with a set of parameters, where I take a random value from a known distribution to calculate a singe run of the simulation. However, for ...
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3answers
60 views

What is the difference between doing a linear regression and exhaustive descriptive statistics?

I'm doing a report of the differences between women and men in their performance on a test with variables like: age, education, race and of course genre. I have two options: doing a linear ...
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1answer
41 views

Why run a post hoc wilcoxon signed rank test after Friedman test, why not just skip to Wilcoxon sign test instead?

I understand that one is required to run post hoc tests after the Friedman test. For example, while the Friedman test may find a statistically significant change amongst 3 treatments, one may follow ...
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1answer
34 views

Does descriptive research have dependent varibles?

I am doing a research proposal for a descriptive study to identify the health beliefs and perceptions among women to mammography breast cancer screening. I am using a Likert scale that is divided into ...
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2answers
24 views

Can I obtain the means for two groups using their mean difference?

I have a study which provides the mean difference for two groups (alongside 95%CI, SE, n and p-value). I would like to extrapolate the raw means to use in Revman to perform a random-effect SMD meta-...
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0answers
22 views

Difference between volatitlity of Annualized return and Annualized volatility of returns

I have a series of monthly returns on financial data. My goal is to estimate the volatility of 10 year rolling returns. I am a bit confused on two options. a) Calculate 10 year rolling returns, ...
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1answer
42 views

Clear explanation of Cronbach's Alpha

I have difficulty in understanding Cronbach's Alpha's formula. I searched for google and StackExchange able to understand it. Even there are some topics trying to explain it intuitively, I could not ...
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116 views

Non-direct measurement and degrees of freedom

Background and current intuition In statistics, degrees of freedom are used to characterise the number of independent observations after some statistic has been calculated. The most common example is ...
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19 views

Checking that partition is not “random” [closed]

Suppose there is a set of objects. Each object has its coordinate on a sphere and one scalar feature. Imagine that someone divides these objects into several non-intersecting subsets. And we have to ...
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35 views

What are methods for computing the descriptive statistics of interval measures?

I do several measurements and obtain for each: $m_i = x_i \pm \delta x_i$. What are the mean and the standard deviation of a such series of measurements?
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1answer
33 views

Cronbach's alpha vs. Average Item-Sum correlation?

I have heard that Cronbach's alpha is used to measure reliability of a test (to check if a set of items/question are measuring the same construct). How does the Cronbach's alpha compare with the ...
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1answer
54 views

Identification from minimum value of truncated distribution

Suppose that a given population is endowed with a pair of characteristics $T$ and $K$. Let's think of these characteristics as random variables $$(T,K) \sim \operatorname{BiNormal}((\mu_T, \mu_K), (\...
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24 views

How to approach analyzing a dataset of baby speech?

I've been collecting speech data for my baby brother (who is now 6 months old) with the intention of doing computational analysis of the development of his speech patterns. I haven't much deep ...
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0answers
7 views

How to form indices to rank importance based on two variables?

I have two variables: average absolute difference of car grades for every two auctions, and count of vehicles that were inspected in those two auctions (ex: THA and NA). I have almost two thousands ...
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33 views

How is finding outliers using extreme value theory different from setting threshold on a pdf of normal events?

Suppose we assume that the data follows a Gaussian distribution. We can set a threshold on its pdf to find outliers. How would it be different from setting a threshold on a pdf, fit the exceedances ...
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10 views

Techniques for building growth discovering engine

Since I am trying to analysis and implement similar kind of solution, I am interested to learn about which are the statistical techniques can give me result like this. I know correlation is the one ...
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135 views

Are the following interpretations of EViews output correct?

I just wanted to know if my interpretation of the follow values were right: Std. error (of each independent variable): Indicates the likely sample variability (and hence reliability). Estimated ...
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23 views

What is the sample size in this experiment?

We have to determine the sample size in the following experiment. We are trying to determine the concentration in which a combination of drugs works the best against cancer cells. This involved cell ...
3
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1answer
32 views

Practical use of descriptive statistics

I'm working with a data set in stata that contains information on how much each customer spent on service a, b, c, and d. But most customers don't have every service and this has resulted in a lot of ...
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11 views

Label reduction on dataset

This question related to this other one, for which I have devised a strategy and now want some feedback on it. My data consists of 434042 rows, each corresponding to an observation tagged with 1 of ...
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28 views

Is it ok to ignore data in this instance?

I'm running a program in python I wrote to look at the first spiking time of a neuron in a stochastic network. I'm running about 2500 realizations for each set of parameter values to calculate the ...
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30 views

Reducing number of labels in a dataset

I have a dataset that contains of 13 variables, of which: 5 are binary (T/F). 4 are categorical. 1 is ordinal (ranking). 1 is continuous. 1 is the time component. 1 is a final categorical variable, ...
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16 views

People detection in a supermarket zenital video

I am programming a people detector in a supermarket environment. I am using a dataset that I built from an example vídeo with 500 people and 500 background pictures which have 128x128 size with HOG ...
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1answer
41 views

Measure of central tendency for periodic variable (hour of day)

I have a dataset that shows, for each group, the number of times a certain action was completed during each hour of the day. ...