# Search results

1. ### Interpreting the COX Model

Cox isn’t an acronym. Just a name.
2. ### R [ugly] and R [studio]

I honestly haven't learned or started using R enough to know! I can never find how to update the R ugly (is it called Gui?), only the packages installed. With R, consider me someone who basically downloaded it and tried to create some objects 1-2 times so far. I've installed many more packages...
3. ### R [ugly] and R [studio]

Not sure the official name of the ugly bare-bones syntax interface for R, sorry. If I install/update a package in the R[ugly] is it automatically installed/carried into R studio? If not, is there an easy way to make this happen?
4. ### Linear Regression slopes- can you predict an acceptable slope range?

Like many things in medicine (I'm guessing, unless you're more PhD in virology type), the "standard" is arbitrary and often misses the intended mark. Can you ask your advisor why an R-squared of >.9 (or did he actually mean correlation of .9 and r-squared of >.81?) and how .9375 and 1.0625 for...
5. ### EASY! Which analysis?

That assumes a linear relationship between the values. What if the relationship is better represented by some nonlinear function (maybe extremely high and low values differ by different amounts than one another and differently from middle values, for example)? Which way are you working? Are...
6. ### PPM calculations for 6 Sigma

Please define your abbreviations. There are many different meanings for the same letters...
7. ### Sum of questionnaire score - ordinal vs interval? and choosing an inference test

Rather than matching I would read up on either a rank regression or a proportional odds (ordinal logistic model) so you can just include covariates (Baseline score and others) directly in a multiple regression with the treatment variable as a dummy.
8. ### Sum of questionnaire score - ordinal vs interval? and choosing an inference test

I think ordinal, generally speaking, although some people argue with enough levels to an ordinal variable you may approximate an interval scale (I don’t necessarily agree). I think it’s inappropriate to pretend a bunch of ordinal items suddenly become interval scale because we summed them. The...
9. ### What kind of test for comparing right-skewed data?

I think the answer is yes and no-- @Karabiner is probably referring to the fact that with two groups the central limit theorem may be applicable, or he may have been making the distinction that the data (unconditional Y) need not be normally distributed so long as the errors are drawn from a...
10. ### Anova Data

It sounds like, currently, you have a variable (let's call it "A" for now) with 4 options: Campus Male, Campus Female, Online Male, Online Female. I'm suggesting you "decompose" this variable into it's components of Gender and Mode of Learning (call it "Mode"). For the "Gender" variable, tell...
11. ### Anova Data

Create a new variable for gender and another for learning mode.
12. ### What kind of test for comparing right-skewed data?

I don't particularly think either test recommended by @CamilleJosion would be very appropriate given that each individual has 10 measurements. This is a kind of repeated measure design, unless you have reason to believe biopsies on the same person are in no way related (which doesn't make too...
13. ### Constructing intervals VS hypothesis testing?

Intervals A and B can overlap but represent a significant test of hypothesis for a difference as long as the point estimate of one is outside of the other interval.
14. ### What kind of test for comparing right-skewed data?

So you'd like to see if the area of adipocytes varies by site? Are the sites arbitrary or important and the same on everyone?
15. ### What kind of test for comparing right-skewed data?

You're still not asking a specific question. If you're in medicine this is basically asking the workup for a cough without knowing any other information on the patient. If you're in biology this is basically asking someone where vertebrates live. What is it that you are hoping to learn, in...
16. ### What kind of test for comparing right-skewed data?

Regarding the title: data are neither parametric or nonparametric. Those terms refer to broad classes of statistical methods. Let’s back before determining a test: what are the specific questions you hope to answer?
17. ### Graduate Certificate vs second Bachelors

This is only my opinion. If you want true understanding not only of what you learn formally but a deeper ability to teach yourself new methodology and theory (which happens a lot once you’re out of a degree program), and if you’re truly passionate about statistics, I would suggest the bachelors...
18. ### Can I use Multiple Regression on my data?

So FOC is frequency of checking, and is the dependent variable, I would say you could use an ordinal logistic regression (not a linear regression model). Both can be "multiple" in the sense that they can employ more than one x variable (predictor). For FOC, do you only have responses as "never"...
19. ### Can I use Multiple Regression on my data?

@hlsmith makes a good point. How is "frequency of new mother checks" defined and measured? Is it total checks in a 24-hour period? is it the number per hour? better explanation will be useful in making sure the model is specified appropriately since it sounds like a bounded count would be the...
20. ### Regression Analysis

You can have severe MC in the presence of individually significant coefficients, but overall, the VIF or tolerance should only be one piece in the puzzle and you need to decide if prediction or inference is more your goal. If prediction, I think the bigger concern is that the pattern of MC holds...