Correlation
This type of graph is used for correlational studies
What is a scatterplot?
lm(house_cost ~ size)
In this equation, the independent variable.
BONUS: What is predicting what?
What is size?
BONUS: size is predicting house_cost
Boxplots can reveal this property of data
What are outliers?
Satisfaction ratings (very, neutral, not)
What is ordinal?
This test can be used to assess normality.
What is the shapiro test?
True or false: Nominal variables can be used for correlations.
What is False?
the command: summary(dataset)
will give this information.
What is mean, min, max, 1st/3rd Quartiles?
BONUS: # of NAs
Identify the dependent variable from the following vignette:
A researcher wants to study the effect of visual acuity on reading comprehension. Students are given vision and reading tests.
What is reading comprehension?
Mental health scores
What is interval?
This test uses a categorical variable of more than 2 types to predict a continuous variable.
BONUS: This test can be used to assess equal variances between these input variables.
What is an ANOVA?
BONUS: What is Levene's test
Finding the line that best fits a correlation is this type of statistical test.
What is linear regression?
Describe this model:
lm(happiness ~ money*job_satisfaction)
What is: a linear model predicting happiness from the interaction of money and job satisfaction?
This term describes the assumption that errors should be roughly equal size across the independent variable
What is homoskedasticity?
Education level (high school, BA, MA)
What is ordinal?
This test uses one or more continuous variables to predict a categorical outcome.
BONUS: name the glm family
What is logistic regression?
BONUS: binomial
What is 36%?
This predictor explains the most variance:
Estimate Std. Error t value Pr(>|t|)
(Intercept) 37.105505 2.110815 17.579 < 2e-16
hp -0.031157 0.011436 -2.724 0.01097
wt -3.800891 1.066191 -3.565 0.00133
disp -0.000937 0.010350 -0.091 0.92851
What is 'wt'?
Residuals from a linear model can be tested for normality using this approach
What is a q-q plot?
[Also: histogram, also Shapiro test]
Species type (mammal, fish, reptile)
This test uses one or more continuous variables to predict a continuous outcome.
BONUS: name the glm family
What is linear regression?
BONUS: Gaussian
True or false: Comparison of the strength of correlation between A & B and A & C is best assessed with multiple regression.
What is true?
This model explains the most variance:
A: R2=.67, AIC = 850, F=85.12
B: R2=.67, AIC = 950, F=83.80
C: R2=.76, AIC = 480, F=126.3
D: R2=.76, AIC = 520, F=116.7
What is C? (though also need more information)
This type of Chi-Square test compares distributions across categorical variables
BONUS: The other type of chi-square test
What is an Independence Chi-Square test?
BONUS: What is a "goodness of fit" Chi-Square
Temperature (in Celcius!)
What is Interval?
True or false: A t-test and ANOVA of two groups on a continuous variable will produce the same result.
What is true?
BUT you shouldn't do this because of the equal variance assumption of ANOVA, and ANOVA doesn't reveal direction of significance: TWO GROUPS = t-test