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JW posted on Sunday, November 04, 2007 - 9:32 am
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Hi, I'm using a MLM estimator with data that is missing at random. I've imputed the following in the VARIABLE command VARIBALE: USEVAR ARE DSRS SSSMINUS CNCEQ CESBQ; MISSING ARE ALL (999); In the analysis command I entered: ANALYSIS: ESTIMATOR IS MLM; TYPE=MISSING H1; If I don't enter TYPE=Missing, my N drops and it seems to do a list-wise deletion. If I include the Type=missing, it uses the full sample, but I get the following error: *** ERROR in Analysis command Estimator MLM is not allowed with TYPE = GENERAL MISSING. Default will be used. 1 ERROR(S) FOUND IN THE INPUT INSTRUCTIONS How do I include the full sample, using MLM and account for missing data? |
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Paul Silvia posted on Sunday, November 04, 2007 - 10:40 am
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For TYPE = GENERAL MISSING H1 and continuous outcomes, only ML, MLR, and MLF are available (see User Guide p. 424). If you use the MISSING option, then the ML estimator is full-information ML, so ML or MLR is probably what you want here. |
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JW posted on Monday, November 05, 2007 - 5:37 pm
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Thanks. I think I'm confused as I do have non-normal data, and should use the robust maximum likelihood estimator, right? How should I handle missing data with non-normal, continuous data? |
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Paul Silvia posted on Monday, November 05, 2007 - 6:12 pm
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One would need to know a lot about the nature of the non-normality (as well as other assumptions that may be unmet), but my preference would be to add the BOOTSTRAP option to the ANALYSIS command, a la: TYPE = MISSING H1; ESTIMATOR = ML; BOOTSTRAP = 1000; (see UG p. 434). And under OUTPUT, add: CINTERVAL (BOOTSTRAP); This will handle the missing data as well as give you bootstrapped standard errors and confidence intervals. |
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JW posted on Tuesday, November 06, 2007 - 5:25 am
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Thanks! This is helpful. James. |
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JW posted on Wednesday, November 07, 2007 - 5:11 am
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Actually, I do have a f/u up question. Is there a way to include missing data with MLM estimator? So, when I did the analyses with boostrapping as you mentioned above, the full N was used, but when just with MLM as an estimator and no missing data command (as the error message occurs), cases were not included and my N dropped. |
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No. Only listwise deletion is allowed with MLM. |
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