# Questions tagged [intercept]

The intercept in regression-type models is the value of the Y variable when all X variables are 0.

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### Can we have intercept in this model: mutually non-exclusive factors

Imagine we have an experiment, where each subject consumes 2 out of 3 different kinds of chocolate bars (Mars, Snickers, Bounty) and we measure blood sugar subsequently, that is, after 2 of the bars ...
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### Should I remove the intercept when I have one dummy variable that covers all the categories in a categorical variable?

I have a categorical variable that has $4$ categories, and I have two dummy variables, $x_1$ and $x_2$, that cover this categorical variable. The $x_1$ variable has values of only $1$ without any ...
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### How to interpret the p-value associated with the intercept?

I ran a gamlss to predict my response variable Y with 2 categorical factors PROTECTION and JOUR ...
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### Interpretation of estimates for 2 categorial factors and their interaction

I selected the best fitted gamlss model for my data : gamlss(formula = Ratio ~ PROTECTION * JOUR, nu.formula = ~JOUR, family = BEINF, data = D_E1, trace = FALSE) I want to interpret the output of ...
1 vote
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### What to set "intercept factor" and "slope factor" as in model?

I was struggling a bit with understanding what exactly the intercept factor and slope factor is in a model. I need to estimate these in an a priori power analysis I am trying to do. My understanding ...
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1 vote
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### Interpreting an estimated bivariate VECM

I have used the tsDyn package in R to estimate a VEC model for the data in the graph, and I am unsure about my interpretation of the output. ...
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### Lmer R: linear mixed model with random intercepts and nested variables

I want to write a model for my data on cell counts in specific brain regions. The multilevel structure of the data is as follows: Measurements within subregions with axes within animal Subregion and ...
1 vote
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### Intercept change issues in growth curve model in R

I am currently analyzing the data using a growth curve model, and I have one question that puzzles me. I wonder why the intercept values keep changing when I add random effects or higher-order terms ...
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### Simple linear regression for market size estimation - understanding the existence of the intercept constant [duplicate]

Background/Context: Over the last year ServiceY has slowly rolled out across the city. The city is divided into geographic divisions of different sizes which all have different levels of demand for ...
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### Latent growth curve model - can I talk about an effect over time if I only have my outcome at the last timepoint?

I have a latent growth curve model with two variables. X (exposure to media) was measured at 5 time points over several years. Y (misinformation proneness) was measured only at the last time point (...
1 vote
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### How to interpret intercept in linear mixed effects with two categorical predictors with three levels?

I'm having a bit of a hard time interpreting the results of this linear mixed-effects model: happy_prob ~ height_shuffle * height_original + (1 | template) Where <...
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### Use centered variables or include an intercept in time series analysis?

I have read that analogous to univariate AR(p) models, there are two possibilities to allow for a non-zero mean with VAR(p) models: a) either use centered variables in the model: Φ(B)(Xt − μ) = Zt b) ...
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### Calculating R-squared (coefficient of determination) from WLS linear regression with zero intercept

I need to calculate the R^2 for a weighted least squares (WLS) regression model which is also a regression through the origin (RTO). I'd like to use it for comparing the quality of the fits for the ...
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### GAM plots: partial effects, shifted y-axis, or predictions - which representations/interpretations are correct/accurate?

I have two GAMs fitted with a Gamma distribution, with the same model structure with a continuous response variable and one continuous covariate, two categorical covariates, and one random effect: <...
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### Intercept in Quantile Regression

We all know that for the OLS model, if you center both $X$ and $Y$, the estimated intercept would be 0. I was curious if we can do a similar thing for Quantile Regression. Would it be possible if we ...
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### Catgeorical variable coefficients interpretation

if I have the following regression model in gamlss (or if it's a general concept) Y ~ var1 Where Y ~ beta, and var1=(g1,g2,g3) g1 is the reference level, what does it mean that the intercept is ...
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### Is it possible to calculate x-intercept from a mixed model?

I understand that the x-intercept can be calculated using $y = mx + b$ for a linear model. I am unsure if this is statistically appropriate for a mixed model with count data, given that counts cannot ...
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### How to interpret intercept of mixed model with time

I am trying to understand the meaning of the intercept in my glmm model summary. I get that is is the prediction when all predictors are 0. The reference levels can be specified so that this is ...
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### Intercept term of a GAM with smooth and factor smooth

I am modeling time-series data (30 measurements) at the individual-level by a grouping factor (5 levels) and I have the following model specification from a generalized additive model (GAM): ...
84 views

### Plotting a regression line with a different fit than the model it is supposed to illustrate

I am currently at a dilemma concerning a model describing the allometric relationship between body size and mass. After carefully checking model assumptions and selecting the model that best fits the ...
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### Regression analysis with constant dependent variable

Can someone explain to me what's going on in the following? Suppose we have data with constant dependent variable: ...
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