Shifting and rescaling data to assure zero mean and unit variance.

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44 views

Standardization before applying ANOVA?

I have a matrix where the rows are the data points (samples) and the columns are the features. It is a multiclass (4 classes) problem. On this data I want to apply machine learning classifiers. But ...
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0answers
23 views

Test-retest correlation for panel data

I've run an experiment in which subjects rate how much they like six different objects on a 1-5 scale on two occasions. I'd like to obtain a summary measure of how consistent are the the subjects in ...
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28 views

What is the name of this procedure?

Frequently, normalization means subtracting the mean and dividing by SD. What if one standardizes the data by subtracting the median and dividing by interquartile range? Does that procedure have a ...
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15 views

What is the limitation with using a pooled standard deviation in a dependant sample?

I am not very experienced in statistics, but want to perform a meta-analysis on a number of pre-post studies. The studies have relatively small sample size ranging from around 10-38 subjects. They are ...
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45 views

Normalization or standardization for distances in a Q-mode cluster and principal components analyses

I want to run a cluster analysis and a PCA between some sites to classify them in terms of their multivariate dissimilarity. This is a Q-mode analysis. I am working on a data matrix made of sites in ...
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1answer
30 views

Backtransforming the vertex of a quadratic function

I have created a model for which it was necessary to scale my predictor values by subtracting by the mean and dividing by the standard deviation of the X values. This resulted in variables centered ...
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149 views

Standardized VS centered variables

I have found many useful posts about standardized independent variables and centered independent variables on stats.exchange.com, but I am still a bit confused. I am asking you an evaluation of what ...
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0answers
26 views

When to standardize data [duplicate]

I have a big dataset of sensor data (body temperature) acquired on a lot of people and each person is assessed for several days. ...
2
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1answer
23 views

Using dummy variables when variable has been standardized

I was wondering if someone can help me with the following. I am using an investor sentiment index that has been standardized to yield a mean of 0 and a standard deviation of 1. This index has been ...
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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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2answers
99 views

GLMnet - “Unstandardizing” Linear Regression Coefficients

When performing linear regression, GLMnet apparently standardizes the dependent variable ($y$) vector to have unit variance before it runs the regression, and then unstandardizes the resulting ...
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30 views

Feature scaling for non-negative sparse data

Imagine you have many observations on which you want to run a classification algorithm. Each observation is characterized by a matrix of non-negative values. For all observations 90-98% of the values ...
2
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1answer
72 views

Standardization for regularized, sparse hashed logistic regression

As the question states, I'm fitting large, sparse logistic regressions (with hashed interactions, a la vowpal wabbit) for a machine learning system. The features are on different scales, and I'm a ...
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16 views

Overlap between 1) regression results and 2) correlation between residualized versions of variables

Scenario: 1) Regress a standardized variable A ("stand. A") on a standardized Variable B "(stand. B"). Since both Variable A and Variable B have a number of potentially confounding influences on ...
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3answers
117 views

Adding Interaction Terms to Multiple Linear Regression

I am currently running a multiple linear regression, and I am bit confused in regards to how to properly add interaction terms to the model by hand. All of the variables I am using are continuous and ...
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1answer
63 views

Is the covariance of standardized variables the correlation?

I have a basic question. Say I have two random variables, $X$ and $Y$. I can standardize them by subtracting the mean and dividing by the standard deviation, i.e., $X_{standardized} = \frac{(X - ...
3
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1answer
46 views

Recovering original regression coefficients from standardized

Suppose I use Least Squares to estimate coefficients in the standard linear model with design matrix $X$'s columns standardized, so the model is $$ E[y] = X^*\beta^* $$ where $X^*$ is $X$ with columns ...
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31 views

Standardize within cohort or standardize within entire sample?

Suppose I'm interested in regressing variable A on variable B. I have two cohorts and want to be sure that there is not an interaction between cohort and variable B, so I include that in the ...
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36 views

Scaling factor in R?

I am implementing a logit model on fraud detection data set which is having several attributes.Target column is truth or fraud.Data contains transaction amount is one of attributes.I generally scale ...
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1answer
31 views

Deriving the mean from a raw and standardized score

My son has received 52 marks in a test. This has been standardized, using a mean of 100 and a standard deviation of 15, as 102.27 What is the mean mark, and how many marks would he have needed to get ...
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28 views

Confidence Intervals of a Given Width

I'm working through some questions on confidence intervals. My answer doesn't match the book, but the book's answer was a number I had a few steps before the end. I have ten numbers which are a ...
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44 views

Standardization/Centering of Longitudinally-measured variable

Could someone possibly help me with the following issues that I am mentally stuck at? Thanks so much! I have 200 variables M1, M2, .... Mx. Each is measured at three time points 0, 30, 120 min. The ...
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1answer
29 views

Should I standardize age in the following situation?

I am a graduate student in biochemistry, and I am looking at cancer death rates for the Canadian population in 2010. Basically, I have acquired from Statistics Canada: 1) The estimates of individuals ...
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0answers
187 views

How to calculate age and sex-adjusted z-scores in SPSS

I have a large data set in SPSS which includes triceps skinfold measurements for children at various ages. I would like to create z-scores for these measurements which adjust for sex and age... is ...
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13 views

Student t distribution: standardization [duplicate]

I got a question concerning the standardization of a student t distribution. I see that the "plain vanilla" t distribution has density $f(x|\nu)=\frac{\Gamma(\frac{\nu+1}{2}) ...
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49 views

Standardization (z-score) across the “Samples” or across the “variables”?

I found in literature that one of the most common way of standardization data is to compute z-scores (mean subtraction and division by standard deviation). Can anybody tell me if it is ok to compute ...
3
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59 views

OLS with ordinal dependent variable - do the coefficients mean anything?

I currently read a paper in which the author has asked people 3 different questions regarding their life satisfaction, all of which are to be rated on a four point scale: 1) very low, 2) low, 3) high, ...
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45 views

Z-score across the “Samples” or across the “variables”?

I found in literature that one of the most common way of standardization data is to compute z-scores (mean subtraction and division by standard deviation). Can anybody tell me if it is ok to compute ...
0
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1answer
76 views

Some issues with standardized variable in a regression analysis

I'm solving this multiple choice question on the properties of a standardized variable. Two of the possible options (which are wrong but look right to me) are 1. It is always normally distributed and ...
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0answers
63 views

How to destandardize PCA scores in R

I ran PCA in R using the principal() function in the "psych" package. Suppose my dataset is called "data" (118 rows and 8 columns). The 8 variables are answers from a questionnaire, with a scale that ...
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1answer
55 views

Standardizing sample factor scores: population or standard deviation

Please note: This question pertains to Q Methodology, a research method used to study people's subjectivity. Q embodies ontological and epistemological assumptions that sometimes differ markedly from ...
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1answer
50 views

How does data standardization affect a classifier?

How does standardization of data (subtracting the mean, dividing by standard deviation) affect classifiers? Namely, how (if at all) do different types of classifiers get affected by such an operation? ...
2
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1answer
98 views

Multicollinearity and interaction terms

My dataset has 2734 observations (but in some speficitations, that number reduces to 1280). I also have interaction terms (in some specifications, even fourth-order terms). As far as I know, ...
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0answers
39 views

Interpreting standardized log coefficients in OLS

I used the log for my dependent variable as well as for some independent variables. Then I standardized all variables. Now I'm not sure how to interpret the coefficients. Are the log and non loged ...
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30 views

Creating A weighted Scorecard using Stats

Im new to forum and have tried reading some articles to solve my problem but had trouble understanding some of it and others might not have been completely relevant. Below I will outline my problem ...
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48 views

Standardizing variables and interpreting coefficient estimates

I standardized my explanatory variables so that each variable has a mean of 0 and standard deviation of 1 to improve convergence of the fitting algorithm and putting the estimated coefficients on the ...
2
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0answers
63 views

Interpretation of scaled data in a logistic regression analysis

I have a variable (distance to road; measurement=meters; see below) that contains a right-skew and percentage data (0-100% based on amount of habitat in a moving window; see example below) in a ...
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0answers
50 views

In penalized regression models, should binary predictors be standardized?

It is generally agreed that in penalized regression models, such as ridge regression, the lasso, and the elastic net, one should standardize the predictors (such as dividing each by its SD) so that ...
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1answer
138 views

Can I use z-scores to compare data measured in different units?

I am trying to compare the accuracy of two different methods of estimating biomass. This data is in the form of percentage cover (and is arcsine transformed). I also have the real biomass values, ...
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119 views

R code for standardized coefficents and model effect size using nlme

I have fit a longitudinal random effects model using nlme and I prefer nlme because I can get p-values. While working with a ...
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2answers
83 views

Comparing within-subject z-scores (survey data)

I have some messy survey data, wherein one group of interest (cut on one self-reported behavior) rated every single attribute (7-point Likert scales) higher than any other group. I think this has ...
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1answer
88 views

Standardizing vs differencing to remove non stationarity

To remove non stationarity in a time series, we can standardize the time series by subtracting the mean and dividing by the standard deviation. We can also keep differencing the time series until the ...
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20 views

Raw values vs SDS for linear regression?

I have data on age, gender, height, weight and a health variable (call it yvar) which is a continuous variable in the range of 50-150. The age is in the range of 5-15 years (a study of children). I ...
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10 views

Calculate trending of content from multiple sources

I'm not fantastically mathematical so please excuse any mis steps. Let me start with what I'm trying to do: I have news sources, for example: A. Washington Post B. TechCrunch C. Krebs on Security ...
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1answer
83 views

Multiple Regression - Converting Standardized Coefficients to Unstandardized

I recently performed a multiple linear regression using a standardized set of data, and I was wondering if it possible to convert the standardized coefficients from the regression into usable ...
2
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0answers
80 views

Estimating mortality rates with direct age-standardization

I'm attempting to calculate the mortality rates of AMI (acute myocardial infarction) in patients (cases) with high bloodpressure, between the years 2001 to 2008. For every case I have 2 matched ...
3
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1answer
49 views

Is there a way to characterize the position of a point in a distribution that takes higher moments into account?

When summarizing a location in a distribution, we can take the mean into account by simply calculating $x-\mu$. We can take the standard deviation into account by calculating a Z score ...
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3answers
79 views

What is a good paper or book to understand standardization and normalization of data with different units of measurement?

I am dealing with data with different units of measurement for NYC neighborhoods and I am trying to build a composite score with it. For example, I have total population by neighborhood, mean income ...
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1answer
33 views

Retrieving the Unstandardised coefficients from a Standardised Regression

Is it possible to retrieve the Unstandardised Regression Coefficients from a Standardised Regression? If so, how is does one do this in order to use the coefficients to make predictions on new data? ...
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159 views

Coefficient value from glmnet

I am running glmnet for the first time and I am getting some weird results. My dataset has n = 139; p = 70 (correlated variables) I am trying to estimate the effect of each variable for both, ...