Linked Questions

4
votes
2answers
16k views

How can you have a non-significant multiple regression model w/ significant predictors? [duplicate]

Possible Duplicate: Not-significant F but a significant coefficient in multiple linear regression How can a regression be significant yet all predictors be non-significant? Significance of ...
1
vote
1answer
2k views

p-value of t-test versus F-test(joint hypothesis) [duplicate]

SAS code : ...
1
vote
1answer
80 views

Why R is not significant (and very low), while all predictors are significant? [duplicate]

I used a network logistic regression to regress five predictors against a dependent. They are all significant, instead the R is not significant and it's even very low. I can understand that it may be ...
1
vote
0answers
22 views

Why is it possible to get insignificant F statistic (p>0.1) but significant regressor t-tests (p<0.1)? [duplicate]

My results show significant t-tests but an insignificant F-test. Is this possible or are my calculations wrong?
3
votes
0answers
17 views

F test fails but t-test does not? [duplicate]

I'm a bit confused about this. I have a model with multiple variables trying to explain the dependent variable. When I use the F test, I don't pass the critical value. But when I seperate the ...
0
votes
0answers
16 views

Can an F-Test be worse than the two single T-Tests? [duplicate]

Normally when conducting an F-Test one is hoping the F-Test of all variables is significant although the single T-Tests yield insignificant results. But can the reverse also be true? That is a worse ...
337
votes
78answers
159k views

What is your favorite “data analysis” cartoon?

This is one of my favorites: One entry per answer. (This is in the vein of the Stack Overflow question What’s your favorite “programmer” cartoon?.) P.S. Do not hotlink the cartoon without the site's ...
69
votes
9answers
45k views

Why is it possible to get significant F statistic (p<.001) but non-significant regressor t-tests?

In a multiple linear regression, why is it possible to have a highly significant F statistic (p<.001) but have very high p-values on all the regressor's t tests? In my model, there are 10 ...
39
votes
2answers
15k views

Simulation of logistic regression power analysis - designed experiments

This question is in response to an answer given by @Greg Snow in regards to a question I asked concerning power analysis with logistic regression and SAS ...
14
votes
2answers
9k views

Multiple linear regression for hypothesis testing

I am familiar with using multiple linear regressions to create models of various variables. However, I was curious if regression tests are ever used to do any sort of basic hypothesis testing. If so, ...
10
votes
2answers
7k views

multiple regression and multiple comparisons

Say I fit a multiple regression of p explanatory variables. The t-test will allow me to check if any single one of those is significant ($H_0: \beta_i = 0$). I can do a partial F-test to check if some ...
81
votes
0answers
64k views

How can a regression be significant yet all predictors be non-significant? [duplicate]

My multiple regression analysis model has a statistically significant F value however all beta values are statistically non-significant. All the regression assumptions are met. No multicollinearity ...
3
votes
1answer
9k views

Not-significant F but a significant coefficient in multiple linear regression

I have a regression with two continuous predictors and one dichotomous predictor in Model 1 and two interactions of each of the continuous predictors with the dichotomous predictor in Model 2. The ...
2
votes
2answers
4k views

Categorical variables in multinomial logistic regression end up converted into binary variables

When I run multinomial logistic regression with some of the explanatory variables as categorical, my algo (glm) turns them in binary variables, automatically. For examples if one categorical variable ...
1
vote
1answer
8k views

How to explain significant correlation between independent and dependent variable but non significant regression test in the presence of mediation? [duplicate]

Possible Duplicate: Not-significant F but a significant coefficient in multiple linear regression In my research, I use Optimism as the IV, Job Satisfaction as the DV and Work-Family Enrichment ...
2
votes
1answer
2k views

If the f-test is insignificant but coefficients are significant, can I use it?

If the linear regression's f-test is insignificant but its coefficients are significant in t-test, can I use this regression and its coefficients? In academic journals, I find people use linear ...
4
votes
0answers
2k views

Non-significant group effect, but LSD post hoc is significant. Why? [closed]

I am performing repeated ANOVAs in SPSS and came across something I don't understand. Basically, the main effect of group (I have three groups) is not significant (p = .062), but the LSD post hoc ...
1
vote
0answers
89 views

Could removing variables improve model prediction?

Coming from a machine learning background, I have long held the idea -throw in all variables and let regularization and cross validation fight against over-fitting. The reason I am posting this ...
0
votes
2answers
52 views

Factors a, b and c walk into a regression … (multicollinearity puzzle)

I have three factors a, b, and c. In the three univariate models y ~ a y ~ b y ~ c a and ...
2
votes
0answers
56 views

If you know a factor is significant, what is a reason why R might think it's not? [duplicate]

I'm running a logistic regression model where anecdotally I expected age to be a very large factor. If you see from the charts I made in Excel before running the model through R, this is how the ...