#1
What is a variable in statistical analysis?
A factor that can change in an experiment
ExplanationVariables are factors that can change, affecting the outcome of statistical analyses.
#2
In a randomized controlled trial (RCT), what is the purpose of randomization?
To eliminate confounding variables
ExplanationRandomization helps in distributing confounding variables evenly across groups, reducing bias in the results.
#3
What is a confounding variable in a research study?
A variable that influences both the independent and dependent variables
ExplanationConfounding variables are extraneous variables that may affect the relationship between the independent and dependent variables, leading to erroneous conclusions.
#4
In statistical terms, what does 'power' refer to?
The probability of detecting an effect when it exists
ExplanationPower in statistics measures the likelihood of correctly detecting a true effect, minimizing the chance of Type II errors.
#5
What is the purpose of a control group in an experimental design?
To provide a baseline for comparison
ExplanationControl groups receive no treatment or a standard treatment, serving as a reference point to evaluate the effects of other experimental conditions.
#6
What is the purpose of stratified sampling in survey research?
To ensure representation from different subgroups in the population
ExplanationStratified sampling divides the population into homogeneous subgroups, ensuring representation from each subgroup in the sample.
#7
What is the difference between cross-sectional and longitudinal study designs?
Longitudinal studies involve repeated observations over time
ExplanationCross-sectional studies gather data at one point in time, while longitudinal studies track subjects over time, allowing for observation of changes.
#8
What is the concept of blinding in a research study?
Hiding information from participants
ExplanationBlinding ensures participants are unaware of certain information to prevent bias in the study's outcomes.
#9
What is a factorial design in statistics?
A design with multiple independent variables
ExplanationFactorial designs involve manipulating multiple independent variables to observe their combined effects on dependent variables.
#10
What is the difference between correlation and causation in statistical analysis?
Correlation is a statistical measure, and causation is a logical connection
ExplanationCorrelation indicates a relationship between variables, while causation implies one variable directly affects another.
#11
What does the term 'p-value' indicate in hypothesis testing?
The probability of observing the given data if the null hypothesis is true
ExplanationThe p-value quantifies the strength of evidence against the null hypothesis, with smaller values suggesting stronger evidence.