A brief numerical description of a set of data.

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2
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0answers
6 views

Determining forecast error of realtime prediction of binary outcomes

Given datasets consisting of a daily prediction and confidence percentage for each of a small number of binary outcomes, what is the proper way to calculate the forecast error of each series and of ...
0
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0answers
24 views

Central Tendency measure for Response time?

Assume a classic scenario where there are bunch of employees and everybody are given tasks to complete on a regular basis and those tasks may or may not have deadlines. Objective is to to find a ...
1
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0answers
41 views

A summary statistic for an unknown distribution

A trial consists of the following: a number is chosen uniformly from $\{1,2,\ldots,n\}$ then put through a function $f$ yielding a value in $\{W, L\}$. (Think successes, failures of the numbers.) Do ...
3
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0answers
56 views

Prove $\sigma^2(aX+b)=a^2\sigma^2(X)$ for discrete random variable

I'm a total newbie to statistics/math in general, so please bare with me. I'm currently reading the book The Cartoon Guide to Statistics, and stumbled upon the following statement (p. 69): $$ ...
0
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0answers
8 views

Should the arithmetic mean of a subset of population data be annotated as sample mean?

If I have population data, and I want to calculate the arithmetic mean of a subset of the population data (e.g. for a certain category of values within a certain range of $n$ observations), is the ...
0
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0answers
6 views

Relationship/Correlation in this data set - does it exist?

Some analysis has been conducted for my business by an external company. The data, as it stands, only really tells part of the story and doesn't provide any real direction. The original study was ...
0
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0answers
8 views

Comparison between the coefficients of two GLMs

I would be happy to have your thoughts on the issue of comparing the beta-values resulting from two different GLMs. Should the beta values be scaled before a statistical comparison? which test would ...
1
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0answers
24 views

Which standard deviation of the cross-validation score?

When doing cross-validation for model selection, I found there are many ways to quote the "standard deviation" for the cross-validation scores (here "score" means an evaluation metric e.g. accuracy, ...
1
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2answers
43 views

Best statistic for measuring prediction accuracy that is robust for outliers

I have recently built a model, designed for prediction. Initially, I chose model A over B - better RMSE and better MAPE. However, after carefully evaluating each prediction on my test dataset for ...
0
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0answers
24 views

Statistic for deviation from uniform distribution

I am analyzing eye movement patterns. The data is from an evenly arranged three-by-three pattern of squares. I have, for each of the nine squares, the total time that a person was looking at it ...
0
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1answer
73 views

least square in muliple regressions

I am trying to understand the impact of changes in the features to the least-square estimated coefficients. Can somebody provide some insight on this question? If you double the value of a given ...
0
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1answer
20 views

determine the mean cost per unit

I have N orders. Each order consist of x units and I know the total cost of each order. If I would like to determine the mean cost per unit do I use approach 1 or 2 listed as follows: (1) Determine ...
6
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0answers
82 views

Anscombe-like datasets with the same box and whiskers plot (mean/std/median/MAD/min/max)

EDIT: As this question has been inflated, a summary: finding different meaningful and interpretable datasets with the same mixed statistics (mean, median, midrange and their associated dispersions, ...
0
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1answer
27 views

How to report decision tree statistics?

I need to do a formal report with the results of a decision tree classifier developed in SPSS, but I don't know how. I know there are really well defined ways to report statistics such as mean and ...
0
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0answers
14 views

Summary statistics for mean of proportions

I have data from 30 subjects, each subject performing 50 trials and making a binary choice (category A or category B). I want to know if overall the preference is for category A or category B. I ...
4
votes
1answer
52 views

Weighted entropy as a measure of diversity

Suppose that you are a company manager and you are looking for a statistical measure that defines the international reputation of your company. So, you collect data on your clients and the countries ...
0
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0answers
8 views

blindly group a cohort of patients

I have a cohort of 26 patients, each patient with two exams, one pre-therapy and one post therapy. For every exam of each patient I have extract some biomarkers and I want by statistical analysis of ...
0
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0answers
28 views

A feature of several items (likert scale) - one score is needed

Currently I am analysing the quantitative analysis data of my final Marketing project in SPSS and I have a doubt: I have conducted a survey with some questions grouped into 4 features (Trust; ...
1
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0answers
29 views

Given a marginal posterior distribution, when should I report an upper limit on the parameter?

I've been utilizing MCMC in the analysis of $\gamma$-ray spectra. For many of my model-parameters, the marginal posterior distributions, $p( \theta_i |X)$ where ($\theta_i\in(0,1]$), are normal ...
1
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1answer
40 views

Normalization of data

Generally the data is normalized with 0 mean and unit variance. Is it mandatory to use this method? Can I normalize data by simply dividing it with the mean of data (which is another normalization ...
1
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1answer
27 views

Aggregating standard deviation to a summary point

I have a range of data (server performance statistics) is formatted as follows, for each server: ...
0
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0answers
15 views

Terminology for a 1-d summary of a high-dimensional space?

Overly pedantic question ahead. Suppose I have a huge matrix M that has a row for everyone who was at Disneyland on some particular date, a column for the person's ...
0
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0answers
6 views

How to combine 2 independent performance measures for drafting athletic teams

We have approximately 130 athletes, each of whom has either 1 or both of a pair of 2 independent performance measures, M1 and M2, which measure absolute performance ability. M1 and M2 are each the ...
0
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0answers
13 views

Is t-student enough for comparing these?

I'd like to compare two methods of measuring compounds quantity on chromatography paper, which we may call method A and method B (kind of like counting the same things using two different machines). ...
0
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0answers
9 views

Generating priors form test statistics, and applying them to reported summary statistics

Hi a very specific question on generating sensible priors. I have estimates of the parameter $\beta$ in the following linear model, for a few hundred variables X separately (adding 1 X to the model ...
1
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0answers
24 views

Please explain the Weight Function

I'm very new into statistics. And I need to find a statistical method to analyse a data set obtained from an experiment. Since I don't have the right to include images I'll try to explain it. The ...
1
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0answers
17 views

What percent of my data should be used for testing?

I have a certain number of potential customers. Firstly, I should test some of them to decide my strategy and implement on the rest. Could you suggest me a statistical way to decide how many customers ...
1
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0answers
17 views

Building confidence interval with t-distribution

I am wondering wether i have to use normal or t distribution in the following situation I have a population of 1000 individuals. I'm interested in $P$ the sum of all $x_i$ where $x_i$ is the value of ...
1
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0answers
8 views

Statistical Measure for Bidirectional Relationships

I have a karma website where you can create a topic and someone can upvote the topic once. People who receive upvotes from another individual tend to upvote topics from the other individual. What is ...
0
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0answers
14 views

How to create an Index of changes to product data

Firstly - I'm a developer with a very limited knowledge of stats / math - so, be gentle. I have a dataset of product categories, and data about each of them, for each day: ...
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0answers
31 views

How to find the joint probability mass function from summary statistics of its marginal distributions?

Let's say I have $k$ random variables $Y_1, Y_2, \ldots, Y_k$ with known expectations for each variable. $$E[Y_1]=\bar{Y_1}, E[Y_2]=\bar{Y_2}, \ldots, E[Y_k]=\bar{Y_k}$$ are known. For all $i \in ...
8
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3answers
695 views

Plotting results having only mean and standard deviation

I am trying to visualize an appropriate plot for the observations in this table of means and standard deviations of recall scores: \begin{array} {c|c c|c c|} & \text{Control} & & ...
0
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0answers
92 views

Central Limit Theorem, Skewed Distribution and outlier detection

I'm trying to see how the CLT can help when trying to detect outliers in a distribution. Say I'm pricing houses in a location and that the resulting distribution of my sample of prices is rightly ...
0
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0answers
5 views

How to retrieve the group of variables most implied in duplicates?

How to retrieve the group of variables most implied in duplicates ? I believe a good start would be to retrieve the ordered list of the most together repeated groups of variables: Given a sample or ...
0
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0answers
6 views

An index of homogenity in answers to poll questions

I've a dataset from an experiment where ppl were asked to answer more times the same question from a closed set of answers we're going to label here as {A, B, C, D}, then I count the number of answers ...
0
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0answers
9 views

Help understanding the following survey weights?

I'm working on analyzing a household income survey. The data is structured by rows, with each row representing a household. The dataset also includes the number of individuals per household. Now, for ...
1
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0answers
17 views

Can I take average value for variables in same category?

I would like to find if there exists theoretical background for taking average of variables. I have variables in the category of information. All of variables are scaled with 5 points, survey ...
1
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3answers
30 views

Adjusting for a bias between experiment and control before experiment

Suppose you are interested in how an introduction of some X causes a change in some metric Y in a population. Normally, you would random sample an experiment and control group, introduce the X into ...
0
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0answers
26 views

Negative value of Specific Combining Abilities (SCA) Variance and Dominance Variance

Being a student of Statistics, I know variance can not take negative value by definition. However, I can across the following two articles (snaps attached) where they reported negative values for ...
0
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0answers
15 views

How to set bin size for computing mutual information from continuous variable?

I want to compute the mutual information between features and my output variable. I was wondering, what is the best way to set the number of bins for each feature? How should be bins interval ? Does ...
4
votes
1answer
49 views

When do we use matrix norm?

When do we use matrix norm? matrix norm is one of the property of a matrix, but I am not sure when I will use it. Do we use it for calculating a upper bound of a matrix? ...
4
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0answers
51 views

Kurtosis, bias, unbiased and statistics

I apologize ahead of time if this is too vague or meta to be a valid question. I've been looking at Algorithms (Sedgewick & Wayne). They define a class stdstats. In that they define min, max, ...
1
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1answer
111 views

What is the difference between capital X-bar vs. x-bar vs. mu [closed]

What is the difference between $\bar{X}$, $\bar{x}$, and $\mu$?
0
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0answers
117 views

How to normalize root-mean-square-error for predicted values of multiple variables with different ranges

I am trying to compare different data mining algorithms (svm, linear regression etc) in their ability to predict a matrix where each column represents a different variable and has a different range. ...
0
votes
1answer
25 views

How to chose the correct analysis to use

I have 2 datasets in R called good and bad. We have looked at 4000 players on good and 4000 ...
1
vote
1answer
16 views

Predicting accuracy using two measure x1 and x2 and state which one is better

I am interested in predicting Accuracy(Y) and am studying different two measure X1 and X2. It could be for instance that I want to predict the accuracy of a classifier , either by measure x1 or x2. I ...
1
vote
1answer
62 views

Can not determine the ARIMA model for data [closed]

I am trying to develop a useful statistical time series model (ARIMA) using auto arima. The program reported that it can not determine the model. Please help me understand the limitations (if any) ...
2
votes
1answer
36 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 ...
0
votes
1answer
29 views

Three Different Regression Results… Why is one so weak compared to the other two?

I have a data set I'm working with, it's roughly 450K rows of data. I'm breaking the data out from a certain column, and that column has three results. After that, I ran a regression analysis for each ...
0
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0answers
17 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. ...