Do you want high or low AIC?
In plain words, AIC is a single number score that can be used to determine which of multiple models is most likely to be the best model for a given dataset. It estimates models relatively, meaning that AIC scores are only useful in comparison with other AIC scores for the same dataset. A lower AIC score is better.
What does negative AIC mean?
The sign of the AIC tells you absolutely nothing about ill conditioned parameters or whether the model is suitable or not. For example, in a linear regression case, if the AIC is positive, you can make it negative (or vice versa) just by multiplying every observation on the dependent variable by the same number.
What is the test statistic for independent samples t?
Test Statistic. The test statistic for an Independent Samples t Test is denoted t. There are actually two forms of the test statistic for this test, depending on whether or not equal variances are assumed. SPSS produces both forms of the test, so both forms of the test are described here.
When do you need to use a nonparametric test?
When the outcome is not normally distributed and the samples are small, a nonparametric test is appropriate. The Kruskal-Wallis Test A popular nonparametric test to compare outcomes among more than two independent groups is the Kruskal Wallis test.
How are χ2assume and other non parametric tests obtained?
As with parametric tests, the non-parametric tests, including the χ2assume the data were obtained through random selection. However, it is not uncommon to find inferential statistics used when data are from convenience samples rather than random samples.
When to use Levene’s test or independent samples t test?
SPSS conveniently includes a test for the homogeneity of variance, called Levene’s Test, whenever you run an independent samples t test. This implies that if we reject the null hypothesis of Levene’s Test, it suggests that the variances of the two groups are not equal; i.e., that the homogeneity of variances assumption is violated.