#1
What is the purpose of a control group in an experiment?
To provide a baseline for comparison
ExplanationControl group ensures a baseline for comparing experimental results, isolating the effect of the independent variable.
#2
Which of the following is NOT a measure of central tendency?
Variance
ExplanationVariance is a measure of data spread or dispersion, not central tendency; mean, median, and mode are central tendency measures.
#3
What is the purpose of a histogram in data analysis?
To display the distribution of a continuous variable
ExplanationHistograms visually represent the distribution of continuous variables, highlighting patterns and central tendencies.
#4
What is the purpose of a scatter plot in data analysis?
To visualize the relationship between two continuous variables
ExplanationScatter plots provide a visual representation of the relationship between two continuous variables, revealing patterns and correlations.
#5
Which of the following is a measure of dispersion?
Standard deviation
ExplanationStandard deviation measures the spread or dispersion of data points around the mean in a data set.
#6
Which statistical test is appropriate for comparing the means of two independent groups?
Independent samples t-test
ExplanationIndependent samples t-test is suitable for comparing means of two groups with independent observations.
#7
What does p-value signify in hypothesis testing?
The probability of observing the data if the null hypothesis is true
ExplanationP-value indicates the likelihood of observing data if the null hypothesis is accurate; lower values suggest stronger evidence against the null hypothesis.
#8
What is the purpose of blinding in an experiment?
To prevent researcher bias
ExplanationBlinding minimizes researcher bias by keeping participants or assessors unaware of treatment conditions.
#9
What is randomization in experimental design?
Ensuring each subject has an equal chance of being assigned to any group
ExplanationRandomization ensures equal assignment chances, reducing bias and confounding variables in experimental groups.
#10
What is the purpose of a pilot study?
To collect preliminary data
ExplanationPilot studies gather initial data to refine experimental design, identify potential issues, and improve study precision.
#11
What does a Type II error refer to in hypothesis testing?
Failing to reject a true null hypothesis
ExplanationType II error occurs when the null hypothesis is true, but the test fails to reject it; accepting a false null hypothesis.
#12
Which type of study design is most suitable for investigating causality?
Experimental study
ExplanationExperimental studies, with manipulation of variables, are best for establishing causality and identifying cause-and-effect relationships.
#13
In a factorial design, how many independent variables are manipulated?
It varies depending on the study
ExplanationFactorial design manipulates multiple independent variables, and the number varies based on the specific study.