Math 121 - Calculus for Biology I Spring Semester, 2012 © 2001, All Rights Reserved, SDSU & Joseph M. Mahaffy San Diego State University -- This page last updated 20-Jan-12

Alternate Entrance to the Lab

This page has been created to provide you with guidelines for what is expected in your laboratory write-ups. The computer labs are designed to advance your educational experience in several ways. The primary purpose of the labs is to use the computer to connect the mathematical concepts of Calculus and dynamical systems to biological problems. The computer allows you to work more complicated problems that are based on real biological situations. Your Computer Labs are divided into questions answered in WeBWorK (60% - individually worked) and a written Lab Report (40% - worked with an assigned partner), which primarily consists of good Excel graphs and short paragraphs written well.

One secondary purpose of the labs is given by the educational goals stated by both the California State University administration and the College of Sciences at SDSU. They include the need of students to work on interdisciplinary problems in a team setting. Thus, my labs are meant to be worked together, so you will need to learn how to work with a stranger much as you might on a project in the "real world" of employment. The ability to work with others has not been something that Universities have done much in the past, but it is crucial to the advancement of science for the future. (This experience is often much more difficult to negotiate than students imagine, but it can be very rewarding.)

Another major goal of these lab reports is the improvement of your technical writing skills. You are expected to write clear succinct answers to the laboratory questions and develop professional looking work in your presentations. These skills are important in any career that you may choose. (Learning how to write well and presenting material in a professional manner is one of the most important skills that you will take from your college education. The teamwork helps to develop good working relationships for sharing knowledge, which is invaluable in future employment and scientific learning.) You will find that if you take a little more time early in the semester to develop good habits and use the proper tools, then it will save you time (and points) in the long run over the semester. Above anything else, do not be afraid to ask questions of me or the other students. Cooperative learning is part of the lab experience.

Below I want to highlight some of my expectations of your lab write-up.

1. The written part of the Lab Reports will usually appear in your WeBWorK questions with the statement "In your lab report..."
2. Answer every part of each question posed using clear, grammatically correct, and complete sentences.
3. The lab report questions are generally asking about techniques for solving problems, modeling concepts, or error analysis. Write clear responses to the questions in grammatically correct sentences that show you understand the principles, which are illustrated in the problem.
4. Use the downloadable material, like Excel spreadsheets, to aid you in producing better results. Follow any specific instructions posted on the Help sheet for each lab.
5. Take advantage of special features, such as Equation Editor in Word, to improve the appearance of your lab report.
6.  Start your labs early and ask questions either in class or by email to make sure you do not waste time on some problem that is easily resolvable. (Occasionally, errors are made on the labs questions and information or hints will be posted as soon as possible on the web.)

A major part of the lab is using the computer to produce quality graphs. The primary graphing tool that we will be using this semester is Excel. Excel was designed to make it very easy to produce good looking graphs for business materials. (This does create some problems for scientific studies.) It is easy to edit the graphs and produce very professional looking results. Below are some comments about graphing with Excel.

1. Your graphs should be a minimum of 3 inches in height and 4 inches in width (the actual graphs, not the window), i.e., do NOT use the default size in Excel. The graphs should be clear and readable to demonstrate the results being exhibited in the problem.
2. You will almost always need to adjust the interval of the domain on your graph. When an interval is specified for a particular graph, then adjust the axes to match the requested interval. For example, when I ask for x in the interval [-5,5], then Excel will usually default to either [-6,6] or [-10,10]. You will have to override the default by scaling the x -axis to [-5,5]. (Double clicking on either axis gives you lots of options for editing, with which you should become familiar.)
3. Always use points (diamonds, circles, triangles, etc.) to represent actual data. (If points alone are insufficiently clear, then you can use points connected by lines.) For theoretical curves and standard graphs of functions, you should only use lines (with only a few exceptions such as discrete dynamical systems, which we will be studying).
4. When graphing a function, you should use about 50 points from the spreadsheet. (This will automatically occur if you take advantage of the graphing template.) An obvious exception is when you are graphing straight lines.
5. You should never have the label "Series 1" appear on the graph. Either you remove the label, such as when there is only a single graph on the sheet, or you adjust the labels to describe the graphs they are labelling.
6. Label your axes and give your graph an appropriate title. Be sure that the labels match the variables and descriptions of the problem.
7. Grid your graphs with both horizontal and vertical grids, so that you have good references with which to compare.
8. When using the Trendline function, you will always want to use the option of putting the equation on the chart, but we do not want to see the R² value for this course. Most of the time you will need to edit the equation after Excel has put it on your graph. Most of the time you will need to convert the coefficients in front of the variables to scientific notation with 3-5 decimal places of accuracy. (Excel sometimes rounds off significant digits needed to get correct WeBWorK answers.) In addition, you will want to change the default x and y to the variables that are in your problem.
9. If you are uncertain of what is being requested, then be sure to ask! One guideline of how your graphs should appear is for you to try to get them to look like the ones in my lecture notes. Another source is the Sample Lab or in the future you can check the solutions to lab problems after they appear on the web.

Hopefully, the list above will make it clear what is expected of your laboratory reports. I believe that the skills you develop in the lab will be the most important ones that you will take with you from this course.