Mini-lab: Accuracy vs. PrecisionMAKE SURE TO START A NEW PAGE IN YOUR JOURNAL – TITLE AND DATA IT.

Brainstorm the difference between accuracy and precisionYOU HAVE 2 MINUTES WITH YOUR TABLEMATES – BE PREPARED TO SHARE.

Definition:Accuracy: How close a measurement is to some accepted, true value

Precision: A term used to describe how close repeated measurements are to each other

YES YOU SHOULD BE WRITING THIS DOWN

Mini-Lab: Accuracy vs. Precision

YOU WILL WORK THROUGH 2 STATIONS TO BETTER UNDERSTAND THE DIFFERENCE BETWEEN ACCURACY AND PRECISION.

THE TWO STATIONS WILL WORK THROUGH ARE LENGTH, AND TIME

Create these 2 tables in your science journal:

Trial Length (cm)

1

2

3

4

5

6

7

8Average:

Station 1: Length Station 2: Time Trial Time (sec)

1

2

3

4

56

Average:

Station 1: Estimating LengthProcedure a) Tear a sheet of notebook paper (DO NOT TAKE FROM YOUR SCIENCE JOURNAL!!!)

into 8 equal size rectangles b) Without a ruler, draw a free hand line that you estimate to be 5.00 cm long on

one of the sheets. Turn the sheet of paper over.c) Repeat drawing of what you estimate to be 5.00 cm long lines on 3 more sheets

of paper, each time turning the sheet over so that you are drawing a line without being able to look at your previous estimates.

d) Now measure the length of each line with your metric ruler. Enter these measurements in the data table below. Remember that you will have 1 digits to the right of the decimal.

e) Hide the first four sheets from sight. Repeat the above process with the remaining 4 pieces of paper, each time turning them over so that you cannot see the other estimates.

f) Again measure the actual lengths. g) Enter the data for both trails on the data tables.

Station 2: Estimating Time

Procedure: (You will need a partner for this lab)

1. Using whatever timing device you have available (timer, watch, phone, etc.) close your eyes and estimate the passing of 20 seconds.

2. When you open your eyes, your lab partner will write down the actual amount of time in your table. Do not look at the time until you have complete all 3 trials.

3. Complete 3 more trials – this time look at the time after try.

Conclusion:ANSWER EACH QUESTION IN COMPLETE SENTENCES:

Station 1: Length:1. Which of your two sets of estimates was most accurate? Use

qualitative and quantitative data to support your answer.2. Which of the two sets of estimates was most precise? Use qualitative

and quantitative data to support your answer. 3. Is the most accurate set also the most precise? Do they have to be?

Explain

Station 2: Time 4. Did your accuracy improve between the first 3 trials and last 3

trials? Explain using quantitative data.5. Did your precision change between the first 3 trials and last 3 trials?

Explain using quantitative data.