Diagnostic measures (such as residuals or some summary statistics calculated from residuals) are used to evaluate some aspect of quality of model fit to data.

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Questionable diagnostics for a binary logistic model

The model including one binary outcome (0/1; incident rate ~1.2%), one main exposure, and 13 covariates. The whole model is significant and the goodness-of-fit is OK. However, model diagnostic is ...
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45 views

Definition of 'Model Diagnostics'

Can anyone help me out with explaining what the term 'model diagnostics' refers to when applied to multiple regression please? In particular, what tests are necessary to check whether your estimated ...
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39 views

Diagnostics for quasipoisson glm for continuous data

I'm a little confused about how to use the quasipoisson family in the glm function. It was recommended by someone that I use it for my analysis, even though the data are continuous - and as such, I ...
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65 views

Statistical tests for comparing Positive/Negative likelihood ratios in two independent diagnsotic tests

I have a problem regarding the comparison of the likelihood ratios in two diagnostic tests. The definition of positive likelihood ratio in screening tests is "the probability of a person who has the ...
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256 views

“Brute force” expected deviance for logistic regression?

A commonly used goodness of fit statistic for logistic regression is the deviance. This is also known as the likelihood ratio chi-square statistic. It is defined as: $$D=\sum_{i=1}^{N}d_i^2$$ ...
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495 views

Diagnostics for GEE in R

I have been checking out which diagnostics to use for a GEE analysis. It seem that influence measures are appropriate (Preisser, 1996). Does anyone know of a package that can be used in R to examine ...
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0answers
3k views

Fitting a zero-inflated negative binomial regression with R

In this thread, I laid out a problem involving fitting a model that attempts to use minor league baseball statistics to predict success at the major league level (explained in full in the thread). ...
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88 views

Can I compare different estimations approaches with AIC?

I'm running two different panel models. Model 1 is a Random Effects regression estimated using Maximum Likelihood and bootstrapped standard errors. Model 2 has the same main dependent variables and ...
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389 views

How to compute sample size to compare two diagnostic tests

I will be performing two diagnostic tests (one is the gold standard, one is novel) on the same subject aiming to establish sensitivity, specificity, PPV and NPV. What formula may be used to compute ...
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28 views

Independence of “residuals” in a Bayesian multilevel hierarchical model

So i'm having some problems realising what model checks I should do after fitting a bayesian model other than convergence diagnostics. Lets say i'm fitting a hierarchical bayesian regression model, I ...
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56 views

what to do with ridiculous but valid leverage points

So I'm having some difficulty fitting a linear model to the data (see other post here glm model fit - can't find a family/link combination that produces good fit). In particular, I'm worried ...
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34 views

How to proceed with nonstationary variables in panels?

In most of the emprical papers using panel data, authors do not seem to "worry" too much aboout the non-stationarity of the individual variables. Yes, there is asymptotic theory for N and T going to ...
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45 views

Refining “good” mixing time estimate

Fix a Markov chain $\{ X_{t} \}_{t \in \mathbb{N}}$ with mixing time $\tau_{\mathrm{mix}}$. Assume that I know some finite bound on the mixing time $\tau_{\mathrm{mix}} < \tau < \infty$, and ...
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561 views

How to verify linearity assumption in linear regression with categorical predictors?

I have used simple linear regression, and I'm now checking that the model meets the assumption of linearity. The model used a continuous response variable and categorical explanatory variables. How ...
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4k views

Collinearity diagnostics disagree - VIF, condition index, and correlation matrix

I'm working with a large dataset consisting of just over 1 million cases. The data are longitudinal covering 14 years and hierarchical with about 500 of the level 2 units. Each case is a criminal ...
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17 views

GLM Diganostic Analysis - What plots actually matter?

In regards to this Poisson approach (How can the Poisson GLM be used instead of logistic regression for the Titanic survival data?). I always thought that Normal Q-Q, Cook's D distance plots were ...
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50 views

Why is my logistic regression fit that bad?

I was requested by a professor to analyze a high dimensional dataset (92 cases, 400+ variables, and a lot of NAs...) of various patient outcomes (gaussian distributed, counts, and binary) and their ...
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20 views

Problems in finding outliers and leverage points in non-linear regression

I'm implementing diagnostic of non-linear regression model $(y=ax^b)$. I'm trying to find out where outliers and leverage points in my model ...
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42 views

Using Half-Normal Plot to Identify Outlying Observations

When we perform linear regression diagnostic, we usually utilize the half-normal plot (available in the faraway package in R) to identify outlying observations. ...
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41 views

How to distinguish suspicious leverages?

Given a linear model and the following hatvalues and influence.measures, how can I say which measurements are suspicious? I mean ...
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21 views

I want to compare two calibrations with R… But cannot find the right answer

I first want to precise that I spent 2 hours searching for an answer, couldn't find something that was answering my question. So basically, I ran two calibration with my diagnostic test, so I ...
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39 views

How do you approach transformations when modeling?

I'm working with a simple univariate dataset and I've built several models for it. Some I think are fairly decent given that datas structure. In order to get a decent model I had to do some ...
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121 views

What convergence diagnostics are appropriate for a Bayesian hierarchical logistic regression model?

Using WinBUGS, I fit several Bayesian hierarchical logistic regression models for the mean of a binary response variable conditional on a set of criteria. I am now using CODA in R to determine if my ...
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82 views

R lmer Model Diagnosis qqnorm

I fitted this lmer model: m1 <- lmer(logR ~ N_g.m.2 * Year + (1|Wh/N_g.m.2), data = CO2_Ratio) Rendering the attached qqplot. ...
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202 views

Model assumptions and diagnostics for proportional hazard regression model with frailty in R

I am wondering are there any assumptions that must be met in the proportional hazard regression model with frailty? I remember that in regular proportional hazard model without frailty all variables ...
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226 views

VECM Diagnostic Test

I have got few questions about VECM and cointegration test. Basically I conducted a cointegration test on two time series (spot vs forward price) by using the Johansen procedure. The results suggest ...
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101 views

What plots should be used for diagnostics for linear mixed model?

Before fitting a linear mixed model, can any plots be used to show a random intercept/slope is justifiable in the model? I.e. these plots may indicate a different pattern for each individual over ...
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68 views

Help in interpreting AUC values from ordinal variables

I would appreciate if someone could explain to me the benefit of using area under ROC for evaluating agreements between two raters. Here is an example from two raters on, let's say, clinical time ...
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50 views

Simulation for model checks for sample size

In the book Bayesian and Frequentist Regression Methods, Wakefield notes that estimators for coefficients in a linear model will be normal if the error terms are normal or if the sample size is ...
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180 views

Has anyone written a package in R to calculate diagnostic plots after clogit (conditional logistic regression)? e.g. leverage

Has anyone written a package in R to calculate diagnostic plots after clogit, conditional logistic regression? e.g. leverage. Or ...
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101 views

How do I go about conducting model diagnostics on WLS?

I'm familiar with the diagnostics required for OLS, however I'm in new territory with a model I'm fitting to data in R, using Poisson regression with GLM. What are the standard methods in evaluating ...
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92 views

Failure detection method

I receive 1000 points per day from installations who produces electricity. Every installation must proportionally produce the same amount of energy. I have to spot failures in those data. The actual ...
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8 views

Autocorrelation of MAPE in case of lack of autocorrelation in residuals?

I'm building a forecasting tool for electricity market (spot power market). The model forecasts spot prices of power for each of 24 hours of next day. I measure its performance for whole days (for 24 ...
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13 views

Diagnostic measure not influenced by transformations of response variable

What are the diagnostic measures (like Cook's distance, H matrix, DFFITS, DFBETAS) that are not affected by the transformation of the response/dependent variable? And why?
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14 views

Logit model simulation - binned residual plot seems to exhibit bias

To understand how to perform diagnostics, I've been experimenting simulating logit models. The binned residual plot makes sense to me as a simple way of analysing whether residuals are distributed as ...
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18 views

Positive predictive value versus false positive rate

A colleague of mine has quoted to me the following: For a given population with a known specificity and a known event rate where a positive test is thought to predict the presence of an event: ...
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21 views

Logistic Regression Diagnostics

I am a bit confused how to assess the results of a logistic regression procedure I ran. Using SAS (on a 60% training set) - The LRT, Score and Wald test and got very low p-values. However, this model ...
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59 views

ARIMA diagnostic testing in Stata

I am using an ARIMA(1,1,0) in Stata. I have already executed estat aroots and wntestq (white noise test) for the residuals. I ...
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0answers
15 views

Does it make sense to standardize residual using $SSE/(n-1)$?

See[Dean and Voss]Design and Analysis of Experiments,1999. pp.105 The authors proposed that we standardize residuals using: $$z_{it}=\frac{\hat{e_{it}}}{\sqrt{ssE/(n-1)}}$$ where ...
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47 views

Tukey Test in Linear Regression Model Development

I am not able to interpret properly the Tukey Test results from a linear regression model i have built. The Tukey Test for the model i believe is to test is the model is linear. Please correct me if i ...
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23 views

Externally studentized residuals

Assume the our model is simply $$Y = X\beta + \epsilon$$ with $\epsilon$~ $N_n(0,{\sigma}^2I)$. If we want to identify the existing outlier in our dataset, we use the externally studentized ...
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39 views

Estimate ROC curve using binormal distribuiton

I am conducting a meta-analysis on diagnostic studies but for each study I have only mean and standard deviation reported. How can I estimate the ROC curve using the binormal assumption in R ? Tks,
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60 views

Practical beginners resource for building a dynamic OLS model

I need to model the current account balance of a country. The regressors are the real effective exchange rate, the domestic GDP and the GDP of the world. I am using data for 30 years (in logs). It is ...
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23 views

Model diagnostic tests for local linear regression

What are some of the model diagnostic tests which are used/ would be suitable to use for a local linear regression model? Note that this is not the least squares linear model, but rather a special ...
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125 views

How to apply diagnostics to regression model from FactoMineR

Many diagnostics to assess regression models are listed on this page: http://www.statmethods.net/stats/rdiagnostics.html ...
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23 views

Combining LR+ and LR- in naive Bayes

I've come across a colleagues who advocates combining both the positive likehood ratios and negative likelihood ratios in the calculation of posterior probability of the likelihood of a ...
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144 views

Arima Models Diagnostics

I'm doing a forecasting using seasonal ARIMA method. I'm using astsa package in r and I'm testing two models that I can't decide which one is better to use than the other The ACf and PACF for the ...
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115 views

How to compare diagnostic accuracy of two tests in unpaired data?

I am wondering whether I can compare diagnostic accuracy, sensitivity, specificity, positive and negative predictive values, and likelihood ratios, between two diagnostic procedures employed in two ...
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51 views

Diagnostics for the analysis of variance model

I have problem with the diagnostic of the one way analysis of variance model (fitted in R). I've checked all the assumptions of the analysis of variance 1) "For each level of the within-subjects ...
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217 views

Test for convergence within Gibbs sampler

I am running a Gibbs sampler for Multivariate Normal times Inverse Wishart posterior distribution with missing data imputation step. I am trying to check if my step of simulating covariance matrices ...