Timeline for Contrasts with interactions
Current License: CC BY-SA 3.0
7 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Feb 3, 2014 at 22:36 | answer | added | crogg01 | timeline score: -1 | |
| Feb 3, 2014 at 22:28 | comment | added | crogg01 | I think you are misinterpreting what you are seeing. Let me set sth. up | |
| Feb 3, 2014 at 22:09 | comment | added | user29689 | summary(model) compares the levels to the intercept (one level) and not the rest. I need contrast to compare different levels | |
| Feb 3, 2014 at 21:59 | comment | added | crogg01 |
you should just be able to see which level of A have more of an impact in R by typing summary(myModel), the contrasts and levels will be displayed there.
|
|
| Feb 3, 2014 at 21:51 | comment | added | user29689 | I do use R, but I have to use jmp in this case. Maybe I have not explained myself properly but I have already modelled the data - fitting a maximal model then reducing to minimal model which is Y ~ A + B + C + A:B. This tells me A has a significant effect but not which level of A, it also tells me A effect depends on B or vice versa - but not which level of A. I can just plot it and compare visually but as I understand it you can do this statistically with contrasts | |
| Feb 3, 2014 at 20:44 | comment | added | crogg01 | If you can type in the formula in JMP you don't have to create the model matrix yourself. In R to get the full interaction formula you would type : Y ~ (A + B + C)^2 (which would also give you the 3-way interaction) or Y ~ A + B + C + A:B for just the A:B interaction. you cannot just model A1:B1 and A1:B2 that would be a different factor (D = 1 if A1, 0 if not A1). Would you consider moving to R ? | |
| Feb 3, 2014 at 20:26 | history | asked | user29689 | CC BY-SA 3.0 |