Introduction to Medical Statistics

These flashcards cover key concepts from the lecture on medical statistics for the Master in Biomedical Engineering.

What is the definition of a population in statistics?

A population is the entire group that you want to draw conclusions about, accurately defined.

What is a sample in statistical analysis?

A sample is a subset of the population that is actually observed, ideally a random subset.

What does the term 'random variable' mean?

A random variable is a variable that takes numerical values which depend on the outcome of a random experiment.

What is the difference between discrete and continuous random variables?

Discrete variables take on a finite or countable number of values, while continuous variables can take any value in an interval.

Define 'independence' in the context of probability theory.

Two events A and B are independent if P(A ∩ B) = P(A) · P(B).

What is a 'probability measure'?

A probability measure assigns a value between 0 and 1 to an event and meets specific axioms of Kolmogorov.

What is the Central Limit Theorem?

The Central Limit Theorem states that the distribution of the sample mean approaches a normal distribution as sample size increases.

What is a confidence interval?

A confidence interval is a range that estimates the true population parameter with a certain degree of confidence.

What are Type I and Type II errors?

Type I error is rejecting a true null hypothesis. Type II error is failing to reject a false null hypothesis.

What does a p-value represent in hypothesis testing?

A p-value indicates the probability of observing the data, or something more extreme, assuming the null hypothesis is true.

What is the purpose of a histogram in descriptive statistics?

A histogram visually represents the frequency distribution of a set of numerical data.

What does R-squared measure in regression analysis?

R-squared measures the proportion of the variance for a dependent variable that's explained by an independent variable or variables.

What is the Wilcoxon signed-rank test?

The Wilcoxon signed-rank test is a nonparametric test used to determine whether there is a significant difference between the medians of paired observations.

What is a linear regression model?

A linear regression model explains the relationship between a dependent variable and one or more independent variables using a linear equation.

What is the significance of the t-distribution in tests for small samples?

The t-distribution accounts for additional uncertainty in estimating the population standard deviation from a small sample.