Biostatistics
(BSc Biol, 1st year, Spring 2023)
Welcome, students and any other curious people that have somehow decided to drop by! For some of the people taking this course, these will be the first and last statistics lessons you'll ever take, so my colleagues and I will try to make the experience as painless, pleasant and formative as possible.
Statistics is of uttermost importance in all of the natural sciences and particularly in any biologist's thought process. Due to time constraints and teachers-to-students ratios, it'll be unfortunately impossible to teach you all you should know and as well as you deserve, but we hope you'll get some basic understanding of the importance of the topic and that, by the time we part ways, you'll feel like learning more about stats at some point in the future.
My lessons might also be the first and last some of you ever take in computer programming. Speaking programming languages will be extremely useful in today's world for each of you, in your profession and elsewhere. The basic principles you'll learn would justify a course by themselves, and R (the specific language we'll try to speak, listen, write and read) is widely used in genetics and in some sectors of molecular biology, ecology, plant sciences and zoology, to name a few. For example, if you ever enrol in the MXX and you manage to study your notes of our course here quickly at the beginning of that master's degree, you'll save yourself lots of trouble (believe me — I've witnessed it!). But producing good notes requires understanding the contents of the course!
Whereas most of the courses you're taking this year will probably be useless in the mid and long term, we strongly recommend you to try to make the most of Biostatistics! Or else you'll regret it!
Syllabus
Profs. L Davila, P Faraldo and myself are in charge of the students of the second half of the alphabet, namely of the following topics:Descriptive statistics
Basics of probability
Random variables. Notable examples of discrete and continuous distributions. Statistical independence
Parameter estimation and confidence intervals in Bernoulli and Gaussian populations
Hypothesis testing in Bernoulli and Gaussian populations
Simple linear regression. Parameter estimation and confidence intervals. Analysis of variance. Prediction
Course materials
The USC online campus for the course contains detailed notes for the theoretical classes, composed by my colleagues, who have been gentle enough to also include my name on them. My classes will be devoted to practical exercises focused on programming with R, while reinforcing the theoretical contents of the course. There are some useful materials below (mostly in Galician) and I may well add more in the future.
In the 2022–2023 academic year, we are happy to have lessons in presence and without masks or extra distances. Therefore, I will not be livestreaming any lessons nor recording them.
Nevertheless, it is a right of all of you not to attend my lessons (e.g., if you need to work to pay for your studies, or if you just prefer enjoying your youth than listening to a guy talking about stuff), so I will be making any script we use at class available via GitHub: https://github.com/fer-cp/usc_biostatistics .
Please don't...
Please don't postpone installing:
R, from: https://ftp.cixug.es/CRAN
The desktop version of RStudio (after R is installed), from: https://posit.co/download/rstudio-desktop/#download . If you're asked to choose a license type, go for the free (as in "free beer") open-source version.
(Only for Windows users; the rest of you are already done.) Notepad++, from: https://notepad-plus-plus.org/downloads/ , which is an improvement of the awful, by-no-means-good Notepad (in the end, we didn't have much time to delve into this, but the TL;DR version would be that you should never ever use Notepad for anything). To figure out if you're need the 32-bit or the 64-bit version of NPP, go to "Control Panel", use the search bar to look for "System" and then click on "System." YMMV depending on the specific Windows distribution. Anyway, the chances are that you have a 64-bit system. Linux users are more than fine with the default editors; MacOS has TextEdit by default, which is enough for this course.
I'm begging you on my knees that at least you try, as soon as you can. Otherwise, we'll waste a lot of time during the classes, which we need for learning intersting stuff.
My goal; your goal
I would like you to forget about grading, but we all have been first-year university students and I guess this is what you first want to hear about (even thought that it should not be your goal at all).
My practical lessons with R will be assessed via one 1-hour exam during class time, on March 23rd. You will be given hints on exercises that will be remarkably similar to the exam. It is expected that anyone that makes a minimum amount of effort gets ≥0.5/0.75 and that anyone who genuinely understands everything and isn't extremely unlucky/nervous on exam days gets 1.5/1.5.
Your goal should be to:
Get some basic understanding of computer programming because, once you speak a programming language you can:
Perform everyday tasks on your computer that you couldn't perform (easily) before.
Learn how to speak any other computer language very easily.
Have lots of fun! (I'll do my best to prove it, but first we need to start with some slightly boring stuff.)
Learn a few essential notions of statistical thinking.
Produce nice, short handwritten summaries of what you learn, to help you remember what you've learnt when you need it some day, maybe within years (e.g., your master's degree or your job).
Be able to learn independently in the future, both R and statistics. Learning stuff by heart is so 20th century! The best you can learn from me is how to learn.
My goal is to persuade you that the above is your goal, and to help you achieve it. Forget about the grades — they're going to be good if you focus on the actual goal and, if not, it means that we (or any professor who does) are terribly unfair and you shouldn't care about how we value your work.
Student feedback (2023)
I really appreciate it if you leave your feedback via the following anonyous form: https://forms.office.com/e/rDS0FNYbnE . I try to be less of an atrocious teacher year by year.
2023 exam
This is the definitive version of the verrrry interrrresting document for the March 23rd exam.
TYPO! On exercise 23(iii), there's a 1 instead of a 2.
Handwritten summaries
I encourage you to handle in your handwritten summary of what you studied with me, using an online form, on March 22nd at 22:30 CET as the latest. For historical interest, here you have the notes I composed when I was much younger. Do not simply copy from it: it does not cover the same topics as we saw on class.
We know it happens...
<⌒/ヽ-、___ ZZZZ...
/<_/____/
∧_∧
( 0ω0) ¡O wórbuk!
_| ⊃/(___
/ └-(____/
<⌒/ヽ-、___ Ah non, k son universitario.
/<_/____/ ZZZZ...
∧_∧
( ÔωÔ) ¡HOTIA, AS PRÁCTICAS
_| ⊃/(___ DE BIOESTATÍSTICA!
/ └-(____/
FAQs
Why is this site in English? My website is all in English because it's aimed at a general audience; including international colleagues and friends, and exchange students. Plus, you really need to understand statistics and computer programming texts in English, if you want to to learn independently in today's world. So don't complain so much! :) That said, I tend to write the material that directly targets students in Galician, since someone has to use our language in higher education (the USC is one of three universities in the world where one can study a BSc in biology in Galician!).
I have doubts related to statistics and/or the course. Can I ask them to you? Although I'm not being paid for these classes and they take time away from my actual and poorly-paid job, I'll be happy to help you learn about any topic that is (in)directly related to the course. That said, I have no knowledge on how the final exams will be nor about the assessment criteria or what happens in the lessons I don't teach. For any purpose related to studying for the course per se and the final exam, or if your goal is simply getting good grades, please contact the course coordinator ( mariadelosangeles.casares.decal@usc.es ) or the most appropriate of your real professors ( lauradavila.pena@usc.es , pedro.faraldo@usc.es ), depending on who taught what you want to ask about.
Can I get interesting material for preparing your part of the course via an private tutor or older friends? Yes, you can. But it won't be better than what you can find on the 2021 course page (warning: I still don't know the amount of changes I'll introduce). I firmly believe everybody should have access to the same information and that, therefore, all exams should be public.
Can I contact you regarding other issues? Can I contact you once the course is over? Yes and yes. I've received valuable help from university staff in the past, with various personal and academic problems. If you don't know whom else to ask or if you feel that you trust me for whatever reason, please don't hesitate to contact me, regardless of whether we're in 2023 or 2026.