Experimental planning and biostatistics in biotechnology

A.A. 2021/2022
Crediti massimi
Ore totali
AGR/17 BIO/10
Obiettivi formativi
The aim of the course is to provide fundamental knowledge and practical techniques to analyse biotechnological data applying descriptive statistics, inferential statistics and hypothesis testing to understand and perform the most appropriate analysis. The course also aims to provide the basic tool to generate and analyse common experimental designs in biotechnology. Besides theoretical classes, close attention will be given to computer sessions.
Risultati apprendimento attesi
Students will acquire the following skills: 1) organize, summarize and represent biotechnological data; 2) define the appropriate experimental design; 3) use the appropriate standard errors and confidence intervals; 4) realize the appropriate statistical test on data; 5) understand and comment the output of a statistical software.
Programma e organizzazione didattica

Edizione unica

Primo semestre
More specific information on the delivery modes of training activities for academic year 2021/22 will be provided over the coming months, based on the evolution of the public health situation
Introduction: descriptive and inferential statistics. Samples and populations. Types of variables: qualitative, quantitative. Precision and accuracy. Theoretical class 2hrs
Data visualization: Absolute, relative and cumulative frequency tables. Representing the frequency distributions, diagrams and histograms, percentiles and quantiles, contingency tables. Scatterplot, line chart, maps. Theoretical class 3 hrs - practical class 2 hrs
Describing Data: Measures of location and dispersion, geometric and arithmetic mean, median, mode, interquartile range, range of variation, deviation, variance, standard deviation, coefficient of variation. Theoretical class 3 hrs - practical class 3 hrs
Estimate with uncertainty: sampling distribution, standard error and confidence interval. Theoretical class 2 hrs - practical class 2 hrs
Probability: basic rules, Venn diagrams, probability trees. Sum the odds. Independence and the product rule. Conditional probability. Theoretical class 2 hrs - practical class 1 hr
Hypothesis testing: null and alternative hypotheses and statistical significance, P-value. Hypothesis testing and confidence intervals. Error of first and second species. Theoretical class 3 hrs - practical class 1 hr
Analysis of proportions: binomial distribution. Estimate of the proportions: confidence interval and standard error of a proportion. Chi-square test and the goodness of fit. Poisson distribution. Contingency tables for the analysis of categorical variables and chi-square test for the analysis of contingency tables. Theoretical class 4 hrs - practical class 4 hrs
Normal distribution, formula, assumptions and properties. The central limit theorem. Normal approximation for binomial distribution. Theoretical class 3 hrs - practical class 2 hrs
Inference in a population with a normal distribution: t-distribution, assumptions and properties. t-test for one sample. Comparison between two means, paired comparison between means, comparing the means of two samples. Theoretical class 3 hrs - practical class 2 hrs
Comparisons between means of multiple groups: analysis of variance. Theoretical class 3 hrs - practical class 3 hrs
Measurements of relationship between variables: covariance, correlation and linear regression. Least squares. Linear regression. Theoretical class 4 hrs - practical class 2 hrs
Guidelines for designing experiments: the three basic principles of experimental design randomization, replication and blocking. Determining sample size. Theoretical class 4 hrs - practical class 2 hrs
Metodi didattici
Besides theoretical classes (4.5 CFU, 32 hours), close attention will be paid to computer sessions (1.5 CFU, 24 hours). Biostatistics will be presented with a practical approach emphasizing the rationale of statistical theory and methods rather than mathematical proofs and formalisms. Each theoretical lecture will be combined with practical applications and exercises using simple spreadsheets to analyze experimental data. Besides theoretical classes, there will also be intensive computer sessions
Students can choose to attend this course during the first year (I semester) or the second year (I semester). As the skills acquired from this teaching are useful for experimental internship activities, students are warmly encouraged to attend the course in the first year (I semester).
Materiale di riferimento
Slides of any lecture, exercises, datasets, procedures for data analysis and bibliographic material will be provided by the teacher through the Ariel online platform (www.ariel.unimi.it) at https://pcrepaldib.ariel.ctu.unimi.it/v5/home/Default.aspx
The core text is: The analysis of Biological data - Second edition. Whitlock M.C. Schluter D. Ed. By W.H. Freeman and company
Other reference books will be suggested during the course.
Modalità di verifica dell’apprendimento e criteri di valutazione
The exam consists of a written and a practical examination and an oral interrogation. The written part consists of 6 questions (1 multiple choice question, 2 open theoretical questions; 2 practical problems; 1 statistical analysis to comment on, and a computer session with 1 dataset to analyze. The biostatistical test will assess the ability to organize, summarize, and represent biotechnological data by choosing the appropriate experimental methodologies and statistical tests. The oral interrogation will be devoted to commenting on the results of the written and practical examination and to the presentation of an experimental plan. The final score will be the summation of the points from 1-10 of the three different parts aimed at ascertaining:
(a) your knowledge and ability to understand the topics of the course as well as mastery of the specific language related to the use of statistical techniques and the ability to present topics in a clear and orderly manner
(b) your ability to apply knowledge and understanding through the analysis of a dataset or the execution and discussion of a statistical problem using excel
(c) your ability to understand and interpret the results of statistical analysis by commenting on an analytical output of statistical software used during the course and your ability in organize an experimental plan.
The final evaluation is based on a total of 30 points.
Activities carried out by students during the course, such as commentaries on analyses, completion of exercises, a compilation of a dictionary of terms, etc. will also be taken into account when determining the final grade.
Specific procedures for students with disabilities or specific learning disabilities (DSA) will be applied also for telematic exams. Here the complete information:
In case you need specific procedures, please inform the teacher by mail at least 10 days before the exam, including in the addresses ufficiodisabili@unimi.it or serviziodsa@unimi.it.
Esercitazioni in aula informatica: 32 ore
Lezioni: 32 ore
Docente: Crepaldi Paola
Su appuntamento richiesto tramite messaggio e-mail
Sezione di Zootecnica Agraria, I° piano, via Celoria 2