The latent-variable tag has no wiki summary.
2
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1answer
41 views
Why does latent variable modelling in regression tend to push R Squared up?
Hypothetically, say I have I have three manifest variables measuring anxiety and three manifest variables (items) measuring stress. Then I want to use both to predict scores on depression, which I'm ...
0
votes
0answers
20 views
Should experimental treatments be treated as exogenous variables in structural equation modelling?
Say I have 2 experimental treatment (e.g. wearing a hat(hat/no hat) & wearing sunscreen(wearing/not wearing)) that are hypothesized to influence 2 latent variables (e.g. perceived sun protection ...
3
votes
1answer
61 views
IRT/Rasch modeling with very large N
I want to fit a 1-parameter IRT model on a questionaire with 15 questions and about six million people. Considering the large N, standard errors aren't essential. It looks like the IRT world is sort ...
0
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0answers
13 views
Are correlations transitive between manifested construct variables and other set of variables?
I have seen here that correlation is not transitive, but I wanted to know if such argument applies when we model our assumptions over a construct.
More specifically, in my model, I have a construct ...
1
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0answers
23 views
Tricky latent parameter problem
I'm reinterpreting the data of some colleagues to see if I can't get at heterogeneity in grouped outcomes. Start with a decay process with two pools:
$$
C_{it} = P_i e^{-k_{i}^{fast}t} + ...
1
vote
1answer
44 views
Latent variable model and graphical models
At first I was under the impression that latent variable models and graphical models were different things altogether, but after reading some papers about the former class of models, it seems they ...
1
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0answers
59 views
Rescale factor scores from factor analysis to latent metric in R
I'm calculating a factor analysis of several variables in R. I want to determine each case's value on the latent variable. When I run the factor analysis, I receive factor scores. The factor scores do ...
1
vote
1answer
74 views
fractions or wholes for the slope in a latent growth model?
When trying to model a latent growth model in lavaan and AMOS respectively, they seem to approach the time spacing of the slope estimates differently. Lavaan defaults to whole numbers increasing by ...
3
votes
1answer
129 views
Will a quadratic and cubic latent growth curve model always have better fit than a linear model?
A conjecture that I have heard is this:
When you add a quadratic or a cubic term to a linear latent growth curve model, the fit will always improve.
Is this correct? Why/why not?
As I have had ...
1
vote
1answer
205 views
High SRMR despite good fit based on other indices in SEM (latent growth curve)
Context: Latent Growth Curve Modeling for continuous variable with 15 time points. One intercept, two slopes (for first and ...
4
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1answer
44 views
Latent variables in Bayes nets with no physical interpretation
In Pattern Recognition and Machine Learning Bishop writes about Bayes networks:
For practical applications of probabilistic models, it will typically
be the highernumbered variables ...
2
votes
1answer
55 views
How to arrive at class probabilities for each case in a GMM using R/OpenMX
I'm fitting a GMM using OpenMX:
...
4
votes
1answer
165 views
Which R package to use to conduct a latent class growth analysis (LCGA) / growth mixture model (GMM)?
I am trying to perform a latent class growth analysis (LCGA) and/or growth mixture models (GMMs) in R. The data I am using is an increasing number of forks of git repositories (discrete variable, not ...
3
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0answers
36 views
Can we reconstruct the hidden (latent) variables after executing EM?
The question is in the title. I know that EM algorithm could do maximum likelihood estimation for models that have latent variables. I would like to know can we get the (estimated) value of these ...
1
vote
1answer
72 views
Confusion related to calculation of conditional distribution
I have this confusion related to the calculation of a conditional distribution
suppose $y_n = N(0,w)$
$p(o_n|y_n) = N(D.y_n,\phi)$
How do I calculate
$p(y_n|o_n)$
Actually I was reading this ...
1
vote
0answers
245 views
Entering panel-data (cross-sectional time-series data) into SPSS
I don't know how to enter pooled data (I have data about 42 countries over 7 years per variable) into SPSS and then run a regression.
So far, SPSS does not assign the observations to a certain ...
1
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2answers
77 views
Latent Variables
Suppose $Y$ is an ordinal variable such that $Y = 1,2,3,4$ corresponds to levels of impairment. So $Y=1$ is the last impaired and $Y = 4$ is the most impaired. What is the purpose of latent variables? ...
3
votes
1answer
123 views
Rule of thumb reliability of scales for using manifest variables in path analysis?
I am using path analysis to test hypotheses in my study. I have been told by a few people in passing that I can use manifest variables rather than latent variables as long as my reliabilities are ...
2
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0answers
72 views
Testing graded response model thresholds for significance?
I have a data set in which two raters have each rated N samples using a 5-point ordinal rating scale. My primary interest is in whether these two raters make significantly different use of those ...
4
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1answer
447 views
Latent variables, overparameterization and MCMC convergence in bayesian models
Sometimes I have a large number of latent variables in a Bayesian hierarchical model to which, but I am only interested in estimating projected transformations of those latent variables (for example, ...
2
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0answers
165 views
Dealing with poor fit in an Item Response Theory model
I'm studying an online course with about 3000 students who each took several quizzes and I'm trying to apply Item Response Theory (using the ltm package in R) to model the questions, determine which ...
4
votes
1answer
845 views
How to reduce number of items using factor analysis, internal consistency, and item response theory in conjunction?
I am in the process of empirically developing a questionnaire and I will be using arbitrary numbers in this example to illustrate. For context, I am developing a psychological questionnaire aimed at ...
0
votes
1answer
1k views
How to transform observed variables to their underlying latent variable in SPSS?
My questionnaire includes 48 questions (observed variables) that represent 8 different factors (latent variables). All the variables are continuous. I need to compute the latent variables before doing ...
2
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0answers
43 views
Estimating the quantiles of a latent variable
I am trying to estimate the quantiles of the function $f(x_i)$ in the equation:
$$
y_{it} = \alpha_i + f(x1_{it}, x2_{it}) + \epsilon_{it}
$$
My current, probably naive, approach is to run the ...
2
votes
1answer
156 views
Using total score from multi-scale instrument in structural equation modeling
I wonder if you can help me to get the right answer to a question about structural equation modeling. Imagine someone trying to validate a questionnaire using component factor analysis that ...
1
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0answers
75 views
How to obtain mean and joint distribution in factor analysis?
I have a factor analysis model defined by:
$x = m + Wz + e$
where $x$ is a p-dimensional visible variable, $m$ is a constant vector, and $z$ is a $n$-dimensional Gaussian latent variable with $z$ ~ ...
2
votes
3answers
127 views
Understanding proxy variable
Can somebody help me to understand a topic? Say in my analysis I have the true variable education ($E$) which is measured by a proxy variable number of years in school ($S$). Here, the error is ...
3
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3answers
607 views
Why LDA (Latent Dirichlet Allocation) works (ie why puts co-ocurring words together)?
I am studying LDA by myself now, but have a very weak statistical knowledge. I have a question regarding Gibbs sampling, one of the methods for inferring the distribution of topics and words-topic ...
1
vote
1answer
373 views
What are the primary differences between Taxometric analyses (e.g., MAXCOV, MAXEIG) and Latent Class analyses?
Recent research has attempted to determine if certain psychological constructs are latently dimensional or taxonic (i.e., including taxons or classes). For example, researchers may be interested in ...
7
votes
4answers
342 views
Why aren't all tests scored via item analysis/response theory?
Is there a statistical reason why item analysis/response theory isn't more widely applied? For instance, if a teacher gives a 25 question multiple choice test and finds that 10 questions were answered ...
2
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2answers
656 views
Where can I find information about using SPSS for EFA and CFA? Is PCA (two samples) and reliability sufficient for scale development?
Context:
I am in the process of developing a scale for my thesis. My advisor has guided me to using SPSS PCA to complete my analyses. Initially we reduced my scale to 3 factors (her insistence), ...
3
votes
1answer
79 views
Sampling considerations in psychometric applications of item response theory
Background
I have developed a recent interest in Item Response Theory and its applications. I am studying clinical psychology and am most interested in polytomous models aimed at modelling ...
2
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0answers
100 views
How to save individual residuals from an observed endogenous variable in a structural equation model?
I am estimating a structural equation model in which two latent variables (with 4 indicators each) and the interaction between the two latent variables predict a single observed variable. I would like ...
11
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3answers
3k views
How to get started with applying item response theory and what software to use?
Context
I have been reading about item response theory, and I find it fascinating. I believe I understand the basics, but I am left wondering how to apply statistical techniques related to the area. ...
2
votes
1answer
228 views
A problem using Bayesian modeling to impute a variable measured with error
I'm trying to fit a basic measurement error model (from Wansbeek and Meijer pg. 191), using a Bayesian latent variable model. The model appear to converge, but on the wrong answer. I've tried all ...
0
votes
1answer
576 views
Is there a difference between an index score and a composite score?
Following on from my previous question on forming scale scores, my sample has 100 people who have answered 10 likert scale questions each on two academic subjects: Maths and English.
The likert ...
2
votes
1answer
707 views
How do I weigh several variables at two levels to create an overall composite variable score?
Context
I am trying to find the correlation between two latent variables. Let's call them A and B.
A has two dimensions. Let's call them Dimension 1 and 2.
B also has two dimensions. Let's call ...
1
vote
2answers
263 views
WLS estimator and bootstrapping in sem package
Is there a way to run the sem function (R sem package) by using WLS method?
Furthermore I have a very small data set (20 observations), can I overcome this problem ...
2
votes
2answers
205 views
Feature selection and latent variables
I would like to know if it is useful (or maybe dangerous) to reduce the number of attributes (by selecting the most informative ones among thousands) before seeking for latent variables or not (in an ...
4
votes
1answer
231 views
Is it possible to fit a multivariate regression model where the independent variable is latent?
I'm trying to fit a multivariate multiple regression model where the independent variable X is latent but I don't know where to start (I have prior information about the coefficient matrix so I can ...
6
votes
2answers
1k views
How to compute the confidence intervals on regression coefficients in PLS?
The underlying model of PLS is that a given $n \times m$ matrix $X$ and $n$ vector $y$ are related by
$$X = T P' + E,$$
$$y = T q' + f,$$
where $T$ is a latent $n \times k$ matrix, and $E, ...
3
votes
2answers
322 views
When do you consider a variable is a latent variable?
The problem is to define when a variable might be considered as a latent variable. I am interested in how to describe a latent variable, and what are the properties of latent variables.
My twofold ...
4
votes
1answer
144 views
Toy regression question with latent variables
I originally asked this on a machine learning site, but one of the responses made me think that maybe this site is more suitable.
Suppose you have two weighted coins, and every day you flip each one ...
4
votes
3answers
140 views
Estimating latent performance potential based on a sequence of observations
Context
you have 200 observations of an individual's running time for the 100 metres measured once a day for 200 days.
Assume the individual was not a runner before commencement of practice
Based on ...
