Transcript Accuracy and Error

Accuracy and Error
• Accuracy - a measure of how close
your measurement is to the accepted
value.
• How close are you to the Bulls
Eye!!!
• It does not matter if you are above
or below.
Bean Bag Champions Toss
• Be in groups of 4
• Follow the lab sheet instructions
• Only DO part 1, we will work with the data
tomorrow
Accuracy and Error
• Error - the difference between your
measurement and the accepted
value.
Accuracy and Error
• Absolute Error (Ea) - the absolute
difference between your measured
value and the accepted value.
Accuracy and Error
Ea = |O – A|
• Where
• Ea is the Absolute Error
• O is the Observed
(Measured) Value
• A is the Accepted Value
Bean Bag Toss Champions
• Using the formula for Absolute Error, calculate from
the your data collected
Accuracy and Error
• Relative Error (Er) - the size of the
absolute error as a percentage of
the accepted value.
Accuracy and Error
Er = (Ea/A) x 100
• Where:
• Er is the Relative Error
• Ea is the Absolute Error
• A is the Accepted Value
• Calculate the Percent Relative Error for your Bean
Bag data
Precision and Deviation
• Precision - the agreement between a
single measurement and the average of
all of the measurements made the same
way.
Precision and Deviation
• REMEMBER: A precise
measurement may not be an
accurate measurement.
Precision and Deviation
• Deviation is the difference between
the one measurement and the mean
(average) of all of the
measurements.
Precision and Deviation
Da = |O – M|
Where:
- Da is the Absolute Deviation.
- O is the Observed (Measured) value.
- M is the Mean (Average) of several
measurements made in the same way.
• Calculate the absolute deviation for your Bean Bag
toss
Precision and Deviation
• Relative Deviation (Dr) - the size
of the absolute deviation as a
percentage of the mean (average)
value.
Precision and Deviation
Dr = (Da/M) x 100
• Where:
• Dr is the Relative Deviation.
• Da is the Absolute Deviation.
• M is the Mean (Average) of the set
of measurements.
• Calculate the Percent Relative Deviation from the
bean bag toss
• Talk with your team and answer the follow up
questions
Scientific Notation
• Scientific Notation is also called
exponential notation because
exponents (powers of 10) are used
to make it simpler to write large
numbers.
Scientific Notation
• Scientific Notation is also called
exponential notation because
exponents (powers of 10) are used to
make it simpler to write large numbers.
• Example: 2,300,000 can also be
written as 2.3 x 106
Scientific Notation
• The first two numbers (2.3) are
referred to as the coefficient and
consist of the significant figures in
the original number. The last
number is the power of 10 which is
also called the exponent.
Scientific Notation
• This method also works for very
small numbers.
• Example: 0.00045 can also be
written as 4.5 x 10-4
Significant Figures
Arrow Rule for Significant Figures
1. If a number does not have a decimal,
draw an arrow from the right to the left
until you hit a nonzero figure. All figures
to the left of the end of the arrow are
significant.
Significant Figures
Arrow Rule for Significant Figures
2. If a number has a decimal, draw an arrow
from the left to the right until you hit a
nonzero figure. All figures to the right of
the end of the arrow are significant.
Calculations and Significant
Figures
• After you perform the calculation, the
final answer must reflect the value with
the fewest significant figures. The least
precise measurement controls the number
of significant figures.