1. Scientific Measurement Making Sensible Measurements

2. Significant figures Is there a difference between 1, 1.0 and 1.000 Significant figures reflect the precision level to which we know a measurement or result

3. Errors A word used in different ways Has a specific meaning in science – uncertainty Why is this important?

4. Significance of a result To test a hypothesis we have to show that a change in an independent variable results in a change in a dependent variable. Two measurements of body temperature before and after a drug is administered 38.2  C and 38.4  C (38.2  0.01)  C and (38.4  0.01)  C (38.2  0.5)  C and (38.4  0.5)  C

5. Significance of a result To test a hypothesis we have to show that a change in an independent variable results in a change in a dependent variable. (38.2  0.01)  C and (38.4  0.01)  C - significant (38.2  0.5)  C and (38.4  0.5)  C - not significant

6. Reading Errors A type of random error (not systematic) Can be reduced by taking multiple readings – more precise Digital meter – error taken as  5 in next significant figure (3.360  0.005)V

7. A challenge Aim: to calculate the volume of a cylinder scientifically First, measure the length and radius What is the error in your measurements? Calculate the volume using an appropriate formula Refer to the “combination of errors” sheet to work out the error in your result

8. Combination of Errors