Linked Questions

2
votes
0answers
683 views

How to estimate mean and variance of censored normal? [duplicate]

Supposing I have data which I know is normally distributed, but because the recording process is right censored, how do I estimate the parameters of the distribution?
0
votes
0answers
277 views

Estimate parameters from truncated normal sample [duplicate]

I have a question like this, $X \sim N(\mu,\sigma^2)$ with unknown parameters. Now, a sample of size $m$ generated from X, but filter by X < T, i.e., any number larger than T will be ignored and ...
3
votes
1answer
183 views

Derivation of the censoring likelihood function? [duplicate]

The (right-) censoring of likelihood function is defined as: $$ L(\theta) = \prod_{i=1}^m f(x_i;\theta) \cdot \prod_{i=m+1}^n P_{\theta}(X_j>a) $$ where observations $x_i$, $i=1,...,m$ have ...
3
votes
0answers
29 views

How to include number of not-yet-decayed radioactive atoms in MLE? [duplicate]

Since this question received absolutely zero attention, here's a complete rephrase with the aim of significantly shortening it. I have a potful of $n$ radioactive atoms. I spend $t_\text{max}$ = 1 ...
8
votes
5answers
5k views

Linear regression not fitting well

Sorry for this beginner's question... I have googled this for a while with no success. I do a linear regression using R lm function: ...
14
votes
5answers
11k views

What exactly are censored data?

I have read different descriptions of censored data: A) As explained in this thread, unquantified data below or above a certain threshold is censored. Unquantified means data is above or below a ...
4
votes
7answers
21k views

How to judge if 5 point Likert scale data are normally distributed?

I have read that the t-test is used when the population is normally distributed. How can I determine if my data are normal given that I am using 5-point Likert scale with a sample size of 100? What ...
6
votes
4answers
3k views

Does this graph support the assumption of homoscedasticity?

I do not quite understand when a graph shows homoscedasticity. Can someone please explain this to me with the help of the plot I provided?
12
votes
1answer
701 views

Modelling when the dependent variable has a “cut-off”

Apologies in advance if any of the terminology I use is incorrect. I'd welcome any correction. If what I describe as a "cut-off" goes by a different name, let me know and I can update the question. ...
6
votes
2answers
9k views

Appropriate regression model when dependent variable is between 0 and 1?

I am performing a regression where my dependent variable is the value of a group's Simpson Diversity Index. This index value is constrained by $1/k$ and $1$ (where $k$ is the number of classes), ...
6
votes
2answers
2k views

extremely left-skewed response variable - how do I model this dataset?

This is a histogram showing my response variable. The response is # (or proportion? or percent?) of aphids eaten off of cards in fields, to model predation by natural enemies. Predictors: fixed ...
7
votes
2answers
541 views

How to model number of days in the last week smoking cigarettes (0 to 7 - 'U' shaped)?

I am currently analysing data where the outcome variable is 'U' shaped. The outcome variable asks 'how many of the last seven days have you smoked'. Most responses to this fall in the first (none) and ...
4
votes
1answer
369 views

Fitting distributions on censored data

My question deals with fitting distributions on censored data; for the purposes of clarity, we can consider a continuous distribution which is both left and right-censored. In such a case, the ...
2
votes
0answers
993 views

Interpreting Residual Plots of Multiple Linear Regression in R

I am currently attempting to model student achievement using both categorical (mostly demographic factors) and numerical (exam scores) data. I am specifically looking for an explanation of the ...
2
votes
1answer
349 views

How to do preprocessing for zero inflated variable in multiple regression?

I am trying to build a multiple regression model, and many of my variables looks like this (histogram for time spent in the system). The reason I had such data is because zero is actually represents ...

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