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# Blogs

## Biostatistics Blogs

It is often examples that make ideas understandable to students and current events can be a good source of examples. Case in point. Today in Wisconsin, the issue of the day is the outcome of the recall elections and problems with the exit polling. As a tutor, the outcome isn’t interesting, but exit polling like all surveys is key to the usefulness of statistics! In fact, it gives a great opportunity to illustrate some of the basic (and non-mathematical) ideas and concepts of statistics — usually the ideas presented at the beginning of most introduction-to-statistics courses. Statistical inferences are grounded in some basic definitions and assumptions (in bold). A population is a defined collection of individuals that we want to know some data about and a sample is a group taken from the population that we are going to actually collect data from (Sullivan, 2010, p. 5; Triola, 2010, p. 4). If we wanted to know the actual data about a population, which is called a parameter,... read more

I have tutored several students in biostatistics (SAS, but also SPSS) through WyzAnt, and have picked up a few pointers for tutors and students alike. 1. Professors like it "their way": There are many ways to accomplish the same operation in computer programming, especially in such an extensive language as SAS. However, professors generally will grade down if the student does not do it the way the professor lays out in the homework. "Data steps" are especially risky for this - but I have rarely seen two SAS programmers accomplish the same data editing with exactly the same code. 2. Excel is a great teacher and calculator. The reason it's a great calculator is that you can actually program formulas, and some are quite advanced - t-tests, ANOVA, etc. The reason it's a good teacher is that you can put all your variables on the spreadsheet and even label them, then simply refer to them in formulas. Doing this with an odds ratio (OR) is informative, because as... read more

I've had only one response to my 30+ answers to specific solicitations for tutoring help in Statistics, Biostatistics, Algebra, and Biology since coming to WyzAnt. And that person decided to allow their son to engage a student-peer as a study-partner rather than come to me for help via WyzAnt despite specifically soliciting that help here in the first place. I am beginning to think the WyzAnt business-model is terminally flawed. What do you think? Have you had success in soliciting tutoring engagements where I've failed? What is your trick? Are there more effective "letters of introduction" out there than mine? Tell us what you think. Tell us about your success in marketing your tutoring skills via WyzAnt since I have none to contribute of my own! TV

I'm new to this site and can't wait to help you. Got questions? I got answers! Whether you need some simple study skills and techniques or if you have very specific problems in a subject, I can help. Let me show you how all these subjects work together and are not isolated disciplines that you're never going to use. I'll show you the relevance of each subject and how they're all integrated. Learning is so much fun when you understand why you need to know.

BioStatistics is one of the toughest classes out there... When I first saw some of the problems you had to solve for that class, I realized we were in for a challenge! Even though we got a late start working together, you were able to bring your grade up to a very respectable ____ % in the class. You worked with amazing dedication, in spite of a busy schedule with family, work, and school... My hat is off to you---CONGRATULATIONS!

For most people, solving a problem or a question is not difficult if they have a model to follow and the correct data to plug into the model. Take one of the most basic functions, paying for something at a cash register. If the cashier tells you the Happy Meal costs (with tax) \$4.23, and you hand the cashier a \$10.00 bill, I suspect that most cashiers will give and most people will expect their \$5.77 in change. Oh, you can confuse people and make the problem more difficult (7 dimes, a nickel and two pennies, rather than 3 quarters and two pennies), but these are just "tricks." This works, because for the vast majority of people, this is an "ordinary" occurrence something we've either done or witnessed hundreds of times, and we can intuitively extend our addition and subtraction rules to a new problem. Unfortunately, most classroom topics are taught like the math example above using clear, intuitive, and easily understood examples, but tested using confusing... read more

I am finally winding down the summer this week, with most of my students having taken their final exams last week. Subjects I tutored during the second summer session: Elementary Statistics Biostatistics Physics General Chemistry Physiology Molecular Biology Algebra 1 Algebra 2 English Literature Precalculus Best of luck to all of my students! You have all worked hard and I hope you all get the grades that you were hoping for. Looking forward to a busy fall semester!

P-value (probability value) in statistical hypothesis testing may be hard to understand at times. The best way to understand it is as follow. First one needs to understand that in science the goal is to prove that there are no differences between two (or more) sets of data (for example series of parametric numbers derived or collected about individuals, instruments, or other behaving or sizable objects). Let us imagine two groups with 10 individuals in each group. And we have collected temperature from each person in both groups. One group received aspirin before measurement and the other, the control group, received a placebo (inert tablet). Our goal was to prove that there would be no difference between the two groups (proving the null hypothesis that Aspirin has no effect on temperature). The P-Value is the probability that the result we obtained (i.e. the difference between the two groups in terms of their temperature as a function of Aspirin) is not merely due to... read more