Descriptive Statistics Quiz

Which statement about descriptive statistics is true?

• A prerequisite for the calculation of the mode is the ordinal scale level.

• A prerequisite for the calculation of the median is the nominal scale level.

• In a right-skewed distribution, the mode is on the left.

• In a right-skewed distribution, the mean is lower than the mode.

When do we use the Friedman-Test?

• Two dependent samples, ordinal data

• More than two dependent samples, ordinal data

• Two independent samples, ordinal data

• More than two independent samples, ordinal data

With which statistical procedure can one assess causality?

• Factor analysis, since one can extract latent variables explaining the correlations between the variables.

• Causality cannot be assessed by statistical procedures but by study design.

• ANOVA, since factorial ANOVA is often used for experimental designs.

• Multiple regression, since it consists of independent and dependent variables.

Which approach cannot be used in determining k in k-means-clustering?

• Trying different numbers of k by comparing changes in average distance to centroid.

• Statistically confirming a theoretical foundation for k.

• Having a theoretical foundation for determining k.

• Trying different numbers of k by calculating post-hoc ANOVAs/comparisons.

What is a residual in regression analysis?

• Difference between observed and predicted value.

• Difference between expected and predicted value.

• Difference between two predictors.

• Difference between predicted value and the regression line.

You have several independent variables and a metric dependent variable you want to include in your multiple linear regression analysis. You have no theoretical considerations regarding the impact of the independent variables on your DV. You decide to make the order of entry of the variables in the regression equation solely on statistical criteria, so you perform a...?

• Hierarchical regression

• Standard regression

• Logistic regression

• Stepwise regression

If data are missing by chance for reasons that are unrelated to any observed or unobserved variables, then data are...

• ... missing at random (MAR).

• ... missing completely at random (MCAR).

• ... missing not at random (MNAR).

• ... missing partly at random (MPAR).

What type of multiple linear regression do the patterned areas of this Venn-diagram reflect?

• Sequential (hierarchical) multiple linear regression.

• It does not reflect any type of multiple linear regression.

• Stepwise multiple linear regression ("automatic approach").

• Standard multiple linear regression ("enter-procedure").

What does R squared reflect?

• The value indicates the degree of variance explained by one or more independent variables compared to a prediction based only on the mean of the dependent variable.

• The number of significant regression coefficients

• The proportion of predictors having a significant impact on the dependent variable

• If the relation between the IV variables is positive or negative

Which of the following scores cannot be used for comparing different basic models in hierarchical linear modeling (HLM)?

• Pseudo-R²

• Eta²-ratio

• Akaike Information Criterion (AIC)

• Bayesian Information Criterion (BIC)