# A question is a clear duplicate, but the original question doesn't have an answer - only a (real good) comment. What to do?

Question Compare the statistical significance of the difference between two polynomial regressions in R is an obvious duplicate of question Comparing difference between two polynomial regression models in R (which is an exact duplicate of Comparing difference between two polynomial regression models in R). Now, as the new question is a duplicate of the other two, one should not answer it, right?

However, the user who posted the new question says that the two old questions have answers that are incomplete or unclear for him, given his level of knowledge of statistics. Question Comparing difference between two polynomial regression models in R effectively only has an answer which explains why not to use anova in this case (or better, not to naively use anova), but doesn't explain what to do (it suggests AIC, but I agree with the commenter to the answer that that's not the right thing to do). Question Comparing difference between two polynomial regression models in R has a first comment by user @Roland which in my opinion is great and answers the question correctly. However, it's a comment instead than an answer, and it would seem that the user who posted the new question doesn't understand it. I asked him what he doesn't understand exactly. What would be the right procedure to follow here? Flag the new question as a duplicate and add a more detailed answer, following @Roland's comment? Just flag the new question as a duplicate? Do something else?

• The asker needs to explain what they learned from the duplicate & what they still need to know. Then we can provide the information they need without just duplicating the material from elsewhere that already didn't help them. – gung - Reinstate Monica Aug 22 '16 at 12:05
• A remark: we cannot normally close a Q as a duplicate of another Q that has no answers; only mods can perform such a closure. – amoeba Aug 22 '16 at 12:48
• @amoeba you're right, I should have written more precisely "flag the question for closing as a duplicate" instead than "close". After writing the post I realised that it might be misinterpreted, but since I thought the intended meaning was clear from context, I didn't bother to edit. I will do it now. – DeltaIV Aug 22 '16 at 13:17

• Yes. Indeed, it says This question has been asked before and already has an answer but I find this misleading, and I have voted to close multiple older questions as duplicates of newer questions and this never was a problem and has always (or at least mostly) been approved by the community and other voters. – amoeba Sep 15 '16 at 10:59