PRC Statistical Analysis & Software 2

Question 1

A researcher wants to compare the means of three independent groups. Which statistical test is most appropriate?

Accepted Answer

One-way ANOVA

Answer

One-way ANOVA is designed to compare means across three or more independent groups simultaneously, avoiding inflated Type I error from multiple t-tests.

Question 2

In SPSS, which procedure would you use to assess whether a variable is normally distributed?

Accepted Answer

Explore with Shapiro-Wilk test

Answer

The Explore procedure in SPSS provides the Shapiro-Wilk and Kolmogorov-Smirnov normality tests along with Q-Q plots.

Question 3

Which effect size measure is typically reported alongside a one-way ANOVA result?

Accepted Answer

Eta squared (η²)

Answer

Eta squared (η²) measures the proportion of total variance in the dependent variable attributable to the factor, making it the standard effect size for ANOVA.

Question 4

A Pearson r of −0.72 between study hours and exam errors indicates:

Accepted Answer

A strong negative relationship

Answer

A correlation of −0.72 reflects a strong negative relationship, meaning more study hours are associated with fewer errors.

Question 5

In R, what does the function `lm(y ~ x, data = df)` produce?

Accepted Answer

A simple linear regression model

Answer

The `lm()` function fits a linear model; `y ~ x` specifies y as the outcome and x as the predictor.

(PRC) Professional Researcher Certification Practice Test

(PRC) Professional Researcher Certification Practice Test

PRC Statistical Analysis & Software 2