# Recent content by spunky

1. ### Query about reliability coefficient

Given the way theoretical reliability and validity are defined, it's mathematically impossible for a validity coefficient to be greater than the reliability. A formal proof of this statement can be found in Chapter 3, Section 3.9 of Lord & Novick's Statistical Theories of Mental Test Scores...
2. ### CFA - Chi Square and SRMR - Fit Indices

Mostly yes. The computation of the (sample) TLI could be negative and it essentially implies that the independence model (i.e., the model where all correlations are assumed to be 0) fits the data better than the model you propose. So, yes, it does imply that your model is really bad because it...
3. ### CFA - Chi Square and SRMR - Fit Indices

Yeah, this is definitely a bad model. What's considered an "acceptable" model means RMSEA < 0.06 and CFI >0.90 as per the Hu & Bentler (1999) criteria. There's also the issue of your sample size which Barrett (2006) commented on:
4. ### CFA - Chi Square and SRMR - Fit Indices

What are the values of the RMSEA and the CFI? And what estimation method did you use?
5. ### Messaging apps

Whatsapp! The world's most popular messaging app! I don't get why it isn't so popular in North America!
6. ### Correlation to ratio of two variables from individual correlation.

If we know Corr(1/a, 1/(a+b)), Corr(1/a, (1/(1-(b/a))) and Corr(1/(a+b), (1/(1-(b/a))) we can work something out. Nevertheless, preliminary simulations show me that these various correlations are very, very, VERY close to 0 even if cor(a,b)=0.9999. If the OP can safely assume them to be 0, we...
7. ### Valid use of regression

My posts are infinite and eternal. They can't be deleted. They only transform.
8. ### hypothesis testing: proportions with 3 samples

And how exactly do you account for sampling error if you only offer descriptives?
9. ### relationship between correlation and average

After reading your post it made realize that the problem, as I posted it, is ill-conceived and allows for a variety of trivial solutions. For instance, take two standard normal random variables and add a positive constant (say 2 for argument's sake). They are both positively correlated and one...
10. ### relationship between correlation and average

Ok, I'll bite now because this thread is starting to get interesting. For a bivariate distribution (let's keep it simple), under which assumptions might one be able to claim that a positive correlation implies a larger mean in one marginal than the other? The bivariate normal is obviously out...
11. ### Linear regression heteroscedasticity

This is a good article with examples and solutions to use in R and SPSS: https://scholarworks.umass.edu/pare/vol24/iss1/1/