Math 322 - Biostatistics

Lectures

Here you can find what has been done in the lectures, and from time to time also what is planned for upcoming lectures.

Friday April 24th.

Chapter 12.4 Linear contrasts. t-test for linear contrasts. Bonferroni multiple-comparisons procedure. Unusual observations.

Wednesday April 22nd.

Chapter 12.1-12.4 One-way Analysis of variance (ANOVA). Sum of squares. F-test for ANOVA. t-test for comparison of pairs of means.

Monday April 20th.

Chapter 11.11 - 11.12 Partial correlation. Multiple correlation. Spearman rank-correlation. t-test for Spearman rank-correlation.

Friday April 17th.

Chapter 11.9 Model selection. Choosing variables in a model. Backward elimination. Forward selection. Akaike Information Criterion (AIC)

Wednesday April 15th.

Chapter 11.9 Multiple regression. t-test for multiple linear regression. Effects of adding and dropping variables. Geometry of linear regression.

Monday April 13th.

Chapter 11.9 Multiple regression. Partial-regression coefficient. Standardized regression coefficient. F test for multiple linear regression.

R file 090413_examples.R R commands for doing multiple linear regression.

R file bloodpressure.txt Data set

Friday April 10th.

Chapter 11.7 - 11.8 (Pearson) Correlation coefficient. t-test for the correlation coefficient. Fisher's z-transformation. Normal test for the correlation coefficient. Confidence intervals for the correlation coefficient.

R file 090410_examples.R R commands for working with correlation coefficient.

Article Storks deliver babies (p = 0.0008) A cautionary tale about correlation and causation.

Wednesday April 8th.

Chapter 11.4 - 11.5 Standard errors of regression parameters. t-test for linear regression. Confidence intervals for regression parameters. Standard errors and confidence intervals for predicted values and their means.

Monday April 6th.

Chapter 11.4 Residual component. Regression component. Sum of squares (total, regression, residual). Mean squares (regression, residual). F-test for linear regression. R2.

R file 090406_examples.R R commands for doing the F test for linear regression.

Friday April 3rd.

Chapter 11.2 - 11.3 Linear regression. Regression line. Intercept. Slope. Error term (residuals). Method of Least squares. Estimated Least-Squares line. Prediction.

R file 090403_examples.R R commands for carrying out the method of least squares.

R file estriol.txt Data set

Wednesday April 1st.

Introduction to regression analysis and analysis of variance (ANOVA).

R file 090401_lecture.R

R file cropyield.txt Data set

R file mathability.txt Data set

Monday March 30th.

Chapter 10.8 - 11.1 The Kappa statistic. Introduction to regression analysis and analysis of variance (ANOVA). Information about the project.

Friday March 27th.

Chapter 10.7 - 10.8 Chi-square goodness-of-fit test. The Kappa statistic.

Wednesday March 25th.

Chapter 10.4 - 10.6 McNemar's test. Normal theory approximate test. Exact test. Sample size estimation and power for binomial proportion tests (self study, pp. 416-426). Chi-square test for trends in proportions.

Monday March 23rd.

Chapter 10.3 - 10.4 Fisher's exact test. Calculation of p-value for two sided Fisher tests. McNemar's test for paired binomial samples. Concordant pairs. Discordant pairs.

Friday March 20th.

Chapter 10.6, 10.3 Chi-square test for RxC contingency tables. Fisher's exact test for 2x2 contingency tables. Hypergeometric distribution.

Wednesday March 18th.

Chapter 10.1 - 10.2 Categorical data. Two-sample test for binomial proportions. Normal theory (self-study, pp. 387-390). Contingency tables. Observed table. Expected table. Yates continuity correction. Chi-square test for a 2x2 contingency table.

R file 090318_examples.R R commands for doing hypothesis tests on contingency tables.

Monday March 16th.

Chapter 9.3 - 9.4 The Wilcoxon Signed-Rank test. Rank sum. The Wilcoxon Rank-Sum test.

Friday March 6th.

Chapter 9.1 - 9.2 Cardinal data. Interval scale. Ratio scale. Ordinal data. Nominal data. The Sign test.

Wednesday March 4th.

Chapter 8.6, 8.10 Test for equality of two variances. The F-distribution. Power and sample size estimation for comparing two samples.

Monday March 2nd.

Chapter 8.3 - 8.5, 8.7 Confidence intervals for paired data. Two sample test for independent samples with equal variances. Pooled variances. Two sample test for independent samples with unequal variances. Welch-Satterthwaite approximation.

R file 090302_examples.R R commands for doing two sample hypothesis tests.

Friday February 27th.

Chapter 7.11, 8.1 - 8.2 Standardized mortality ration (SMR). Two sample hypothesis tests. Longitudinal studies. Cross-sectional studies. Paired t-tests.

Wednesday February 25th.

Chapter 7.10 - 7.11 Power of the binomial test. Sample size estimation for binomial tests. One sample test for the Poisson distribution.

Monday February 23rd.

Chapter 7.7, 7.9 - 7.10 The relationship between hypothesis testing and confidence intervals. One sample test for the variance of a normal distribution. One sample test for a binomial proportion (normal approximation and exact methods).

Friday February 20th.

In-class exam Chapters 1 - 6, 7.1 - 7.5.

Wednesday February 18th.

Chapter 7.6 Determining sample size for hypothesis tests.

R file 090218_examples.R R commands for determining the sample size of hypothesis tests.

Monday February 16th.

Chapter 7.5 The power of a hypothesis test.

R file 090216_examples.R R commands for calculating the power of hypothesis tests.

Friday February 13th.

Chapter 7.4 Two-sided, one-sample hypothesis test for the mean of a normal distribution. Hypothesis tests for the mean of a normal distribution with know variance.

Wednesday February 11th.

Chapter 7.3 Acceptance region. Rejection region. p-value. Statistical significance.

R file 090211_examples.R R commands for doing hypothesis tests.

Monday February 9th.

Chapter 7.2 - 7.3 Type I error. Type II error. Significance level. Power of hypothesis test. One-sided, one-sample hypothesis test for the mean of a normal distribution. Critical value.

Friday February 6th.

Chapter 6.9 - 6.10, 7.1 - 7.2 Estimation for the Poisson distribution. One-sided confidence intervals. Hypothesis testing. Null hypothesis. Alternative hypothesis.

Wednesday February 4th.

Chapter 6.7 - 6.8 Interval estimates for the variance. Chi-squared distribution. Estimation for the binomial distribution.

R file 090204_examples.R R commands for estimating confidence intervals.

Monday February 2nd.

Chapter 6.5 - 6.7 Estimators for mean and variance. Unbiased estimators. Standard error of the mean (sem). Confidence intervals. Student t distribution. Interval estimates for the mean.

R file 090202_examples.R R commands for demonstrating estimators.

R file 090202_functions.R R functions used for the examples.

R file birthweights.txt A (made up) population of birth weights used for the examples.

Friday January 30th.

Chapter 6.1 - 6.4 Random sample. Randomized clinical trial. Ways of choosing a random sample.

R file 090130_examples.R R commands for selecting random samples.

Wednesday January 28th.

Chapter 5.6 - 5.8 Linear combinations of random variables. Covariance. Correlation. Normal approximation of Binomial and Poisson random variables.

Monday January 26th.

Chapter 4.6 - 4.13, 5.2 - 5.5 Cumulative distribution function. Binomial distribution. Poisson distribution. Normal distribution.

R file 090126_examples.R R commands for dealing with probability distributions.

Friday January 23rd.

Chapter 3.7 - 3.10, 4.1 - 4.5, 5.1 - 5.2 Bayes' rule. ROC curves. Prevalence. Incidence. Random variables. Probability mass function. Probability density function. Expected value. Variance.

Wednesday January 21st.

Chapter 3.1 - 3.7 Basic probability. Relative risk. Predictive value positive. Predictive value negative. Sensitivity. Specificity.

Monday January 19th.

Martin Luther King's day No class.

Friday January 16th.

Chapter 2 Quick review of basic descriptive statistics.

R file 090116_examples.R R commands for doing basic descriptive statistics.

Wednesday January 14th.

Introduction to R (please bring your laptop with R installed).

R file 090114_lecture.R

Monday January 12th.

Introduction to the course. A simple first example: Are men taller than women?

Data file heights.txt