Interpreting T Test and ANOVA with Violation of Homogeneity of Variance in SPSS

This video demonstrates how to interpret t test and ANOVA output in SPSS when the assumption of homogeneity of variance has been violated. Homogeneity of variance (homoscedasticity) is tested with the Levene’s test. The null hypothesis for the Levene’s test is that the group variances are equal.

[carolinepierard]

Dear Dr Grande,
What do you do when in a factorial anova ( 2 independent and 1 independent , independent variable has great difference in sample sizes) your levene's test is significant?
for a one wat anova you can do a non parametric test...but what about the factorial anova? which non parametric test can i do?
I saw that you should transform your data ??? but this seems very difficult for a beginner like me...
could i use instead of factorial anova, different t -tests?
I'm really stuck here....
txs so much for your answer
caroline

[heidimcgrew]

Can you tell me what to do if your Brown-Forsythe test is also significant please?

[dr.bhallansinghsekhonkvk-m]

Hii Dr. Grande... I have performed ANOVA on two-year data, and error variances were found to be significant. The differences were due to environmental variation (hailstorm on the crop during flowering in the first year), so I explained the results on basis of the individual as well as pooled years. But then I was asked a question by someone, justify why the ANOVA is valid, although the assumption of homogeneity was incorrect. Sir, is it possible to give the explanation on the basis of environmental variation or I have to analyze the data in another way. Kindly give your suggestion?

[andreaserge]

What if the dependent variable is not normal, no equal variances, but you obtained significance p<.05
I conducted a Mann whitney test, but I obteined non significant results.
Which test I should trust?

[kheyseed]

is there any drawback when we do not assume the homogeneity of variance to the interpretation of the hypothesis?

[ejeducate]

What if the assumption of homogeneity of variance has been violated and we run welch and Brown-Forsythe and we still gt sig. level less than 0.05 while the sig.level in the ANOVA table is less thn 0.05. since homoscedasticity assumption is violated can we interpret the ANOVA table even if it is significant? or should we say that since the assumption was not met we cant interpret the results?

[pescmworldwide]

Please, any idea why my Levene's homogeneity of variance test is showing "based on mean" median etc.
Is there anyway I can remove the mean. median?

[maccuswong]

I am doing stats analysis on the quantification of DNA damage under two conditions (light and dark) across 4 time point, the quantity was reduced across time (which seems normal) and some may have decreased to 0 at the third time point, which also 0 in the fourth time point.
Then i used MANOVA analysis for my study, amount of damage under light and dark as my DVs and time as my IVs.
When i did my MANOVA test, the box's test of equality of covariance matrices was not computed because there are fewer than two nonsingular cell covariance matrices.
Then i checked the levene's test of homogeneity of covariance, it is violated in one of the two dependent variables.
Then i checkd the normality test and it is also violated.
May i know which analysis i should use?

[ali.amjadi]

What should we do if it is violated for ANCOVA?

[kerimbenkacem]

Hi dr. Grande. Can you make a video on AVE and CR? (Likert-scale). Thanks in advance :)

[surajguptac]

hello sir, I have a query that can we run one way anova if we have a single group in the independent variable rather than having 2 or more groups in it ?