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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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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11 views

non-parametric test and confidence interval [on hold]

How to do confidence interval using non-parametric test for non-normal distributed sample size (n=400) with unknown population standard deviation?
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11 views

State whether the one-sample t test is an appropriate test statistic to analyze data. If not, then explain why it is not appropriate [on hold]

a) A study measuring differences in attitudes about morality among Democrats and Republicans b) A study testing whether nigh-shift workers sleep the recommended 8 hours per day c) A study evaluating ...
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1answer
34 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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41 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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18 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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34 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
24 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
52 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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21 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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6 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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25 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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9 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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16 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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14 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 ...
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1answer
30 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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10 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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29 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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14 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
34 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. ...
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1answer
14 views

What to report for reliability analysis?

After completing data collection on a reliability analysis where multiple examiners sampled each subject three times, which value should I report for descriptive statistics? If intra-rater reliability ...
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15 views

goodness of fit using chi2gof probability distribution curves in matlab

We have sample data,that we need to make goodness of fit to find the best fit using chi2gof in Matlab this is the used code: ...
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21 views

Binomial vs inverse binomial transform in obtaining moments

I am trying to obtain raw co-moment matrices from central co-moment matrices and I have found formulas for the transition from central to raw moments here . I have also found the opposite, that is ...
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1answer
61 views

Help coming with a descriptive statistic

I have some data about employee performance that I want to create a descriptive statistic for that can easily show at a glance how efficient the employee is. Let's start with some sample data: (The ...
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1answer
43 views

How to compute the central tendency for such a distribution?

Consider an annular region of space. We divide this annulus into four equal regions and we take some measurements in each of the four sectors. Imagine we are measuring something like a particle's ...
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9 views

what statistical test for relationship between categorical variable and scale variable?

I have 66 set of data containing two variables; Culture divergence (1=congruence, 2=divergence) and performance score. I am testing two hypotheses: Culture congruence promotes performance ...
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8 views

Correlation in longitudinal data analysis

There is a thesis claiming a significant negative correlation between variable A and B. It used the ordinary least square controlling for 4 other variables C,D, E, F (some are continuous, some dummy) ...
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19 views

Regular weighted average vs. Kernel Weighted average

I am somewhat familiar with using kernels for density estimation (i.e. KDE), but not so much with using them as weights to calculate weighted averages. I am looking for some intuition on the latter. ...
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1answer
43 views

What is the Distribution of Sum of Squared Errors?

I know this might be a very basic question for anyone, but I'm not sure how to answer it correctly. It was recently asked at an interview. It would be great if someone could help me with answering ...
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10 views

Calculating trends and averages on skewed data?

I'm running analysis on an Audit that has been distributed over the course of a year. There are currently about 40 or so different audits. Each audit contains 90 questions. When the audit was first ...
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2answers
86 views

Best way to report mean±SD of p-values (all values are positive and SD is larger than the mean)

I have 50 p-values. I want to show the mean of these 50 and the standard deviation: 0.06 ± 0.19 The standard deviation is quite large, because although almost ...
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8 views

how does the Qn estimator work

I was given a short introduction to alternative robust methods to the MAD used in statistics, one of them being the Qn estimator. This one is denoted as: \begin{equation} Q_n = d( |(x_i - x_j)|:i<j ...
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39 views

alternative to IQR

I am currently making a short literature study on robust and efficient estimators. Some very well known are the median absolute deviation (MAD) and the interquartile range(IQR). However they both have ...
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1answer
49 views

Comparing two datasets with same variable

thanks in advance for anyone taking the time to read/answer this. I am comparing a ground-sourced dataset versus a satellite-sourced dataset for weather conditions, such as temperature. Both sets are ...
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1answer
17 views

Undocumented Migrants and Parameters

I have a question about using census data to find population parameters. When you have undocumented migrants, there's an issue because your parameters can be inaccurate. An example is proportion of ...
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2answers
79 views

How to profile, visualise and understand large number of groups/classes/clusters in data [duplicate]

I am working on clustering a medium-sized, high-dimensional data set (200k rows; 120 columns). Once I have attempted (multiple) cluster solutions, I would like to profile my clusters and understand ...
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11 views

Is there a natural way to determine a threshold for required number of data points?

Often you want to compute a statistic, but only for entities that meet criteria for having a meaningful sample size. For instance, in baseball you often see a footnote like "among batters with at ...
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4answers
666 views

Graphing small samples

I have a small data set of 14 separate times to complete a task. However I am having difficulty finding an appropriate graph to use to graph the data. If the sample was larger I would use a box plot ...
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1answer
25 views

confirmation and validation of a lab environment versus real life scenario

I'm having some trouble trending turbofan jet engines exhaust gas temperatures (EGT). Data collected shown that EGT measured in the test cell versus EGT measured on-wing while flying is different. ...
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28 views

variable selection before a decision tree

I want to built a predictive decision tree. I have a dataset with +/- 1000 observations and 1500 variables. Can I just built my decision tree (training + validation dataset) with all the 1500 ...
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17 views

How to analyze a Semantic Differential?

1) How do we statistically analyze data from a semantic differential? I have seen the results rendered as a graphic joining each point as such
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12 views

Is it an ANCOVA?

In a study, baseline pulse is recorded. Participants are asked to watch a funny video and a thrilled video for 10 minutes. Pulse is recorded again. The objective of the study is to investigate ...
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4 views

experimental research design

In an experiment, same group of participants are required to test (low and high) visual quality of a user interface. The goal is to find whether perception of usability is affected by any of the low ...
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12 views

Are all right skewed distributions the result of a multiplicative process?

If log normal distributions are the result of a multiplicative process and right skewed distributions become normal once converted to logs (i.e. are log normal). Then, can one generalize and say that ...
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1answer
22 views

How can an intentional timing pattern be demonstrated in temporal data?

I dispose of data showing when a public authority issues different kinds of permits, say, planning permissions and liquor licences. I am interested in finding out whether the timing of one type of ...
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11 views

How to calculate probability of a forecast exceeding an evelope

I'm working on forecasting ship motion, driven by ocean waves. Suppose that the motion has an operational envelop. I've made a two category table based on whether the actual or forecasted values ...
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11 views

Find performance of each group without penalise small groups

I have a table with the following data: UserId, TotalPoints, GroupId I try to find a formula to calculate the performance of each group in the above table. I ...
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1answer
16 views

Equivalent of significance in population data? [duplicate]

I know that significance tests don't make sense on population data. But how then can I figure out if effect sizes are meaningful? Is it purely a judgement call? Background: I have a census for an ...
0
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1answer
25 views

Methodology: breaking multi-regression apart

I have to perform a multiple regression where my independent variable is store visits, while the dependents include hour of day, day of week, and others. I need to do this in Excel. Excel limits ...