Purpose:

The purpose of this lab is to explore the characteristics of a set of data and understand it's relationship to "reality". Along the way we will talk about precision, accuracy, averages, medians, and confidence.

Procedure:

For this lab you will need paper and pencil to record raw data along with meter sticks and a sense of humor. There is a tendency in society to think of science as being completely focused on incredibly precise measurements. This tends to obscure some important ideas about data and how science uses it. In this lab I am going to try and force you to take fuzzy data so certain ideas will be more apparent. Below is an outline of the process we will follow but it is deliberately general since there is a lot to discuss in class before we start. As always in lab, you will need your minds (or at least some significant portion of them). The following are the steps we will take:

• I) Process Description: In any field of work it is important to be able to clearly describe what you are doing. Our first task in this lab was to figure out how to calibrate our measurement tool. Describe each of the important steps in your groups process for determining how long their “pace” is. Be sure to note where you decided to start and stop the measurement, how many times you collected the data, and how you will use that data. No calculations or numbers at this point – that’s the next step. In your description be sure to note how you dealt with the natural tendency to step differently when starting or stopping.

• II) Calibration: We have a cultural expectation that when you write things down you should be clean and tidy. This often leads novice scientists to "process" their data before putting it in the lab report. At a fundamental level this is considered unethical in science. In any report of scientific results the actual data should actually be presented without manipulation or modification. This allows others who are trying to understand or appreciate your work to make their own judgements about the decisions you made in gathering the data. In this part you will present the actual data you and the classmates in your group collected in its full and original glory. Create a table to organize and enter the data so that you are also aware of who took/generated each data point. You will need to label each column so you know that the data represents and be sure to note the units. You will have at least three data points for each person here.

• III) Calculation: Now take the numbers from the previous data table and show me how you calculated the length of your pace. Show at least one of the calculations completely so your reader understands how you did it. Calculate the length of your pace for each test individually so you know the extremes and the average results. Report the average pace length as well as the minimum and maximum.

• IV) Measurement of Hallway: Now it’s time to use your calibrated “pace”. Have each member of the group pace off the length of the hallway (to be determined) independently. Record the data and then repeat the measurement at least once. Determine, for your group, the average, min, and max length (in meters) of the hallway consistent with the data. Show your actual conversion, a complete calculation, from paces to meters for at least one case.

• V) Class Results: In a table list the calculated average hallway length from all the other groups in the class. Identify each measurement with the name of the group or someone in the group. Calculate the class's average, min, and max lengths (in meters) for the hallway.

• VI) Meaning: So how long is the hallway? What does this data say about this question? What is your best estimate? What is the range of possibility? How sure are you? Answer these questions in your own words.

LAB DELIVERABLES (turn in):

Turn in your descriptions and data in one document (thru Turnitin on Bb) that show your work on each of the steps given above. In places where you need to show math calculations you can do your math by hand on white paper and take a jpg to insert or turn in a separate calculation page (hand written) to me directly. If you do this remember to number and reference your calculations in the document you turn in. I DO NOT recommend using Mathtype in Word -- it is very painful and time consuming.