Physics 119 Lab

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Rubric Commentary

A Q U I C K O V E R V I E W O F L A B R E P O R T G R A D E R C O M M E N T S 0

Most Common Errors

     Objectives  Little to no motivation for the experiment Procedures  No mention of why are we performing each step Data  Figure/Table formatting Results   No example calculations No mention of assumptions Conclusions  No mention of validity

Little to no motivation for the experiment

  Some reports merely stated the purpose of the experiment:  “To check the proper calibration of the Spectrometer 2000, 3000, and PWLB 1000.” Excellent reports answered: “Why do we need to do this?”  “In any experiment that records data using sensitive, precise instruments, it is essential that these instruments be in an acceptable condition for use. If these instruments are not working properly, incorrect data will be collected, which will make the results of the experiment flawed and therefore invalid.”

No mention of why we are performing each step

  Some reports listed the steps, or wrote out into words a general walkthrough of the experiment’s procedures.

Excellent reports answered: “Why is each step being performed?”  “During each test, only one filter was placed between the PWLB 1000 and the spectrometer to either block one wavelength or to allow only one wavelength through. This makes the data easier to read and make sense of. Gaps or changes should appear in the data at the precise number of each filter used, meaning that the specified particles were blocked and that the spectrometer is calibrated and ready for future tests.”

Figure/Table Formatting

 Excellent Figures looked like:

Figure/Table Formatting

 Excellent Tables looked like:

Filter

400 nm 600 nm

# Unblocked Wavelength Count

1.00 E+24 Photons 1.00 E+24 Photons

# Blocked Wavelength Count

8.00 E+22 Photons 5.00 E+22 Photons

% Blocked

92% 95% Table 1: Equation 0.1 Data and Results – The data found in this table was obtained in the second part of the experiment which used the 400 nm and 600 nm blockers to test the calibration of the Spectrometer 3000. The final column (% Blocked) was obtained by using Equation 0.1, which gives a percentage of blocked photons to determine if the spectrometer has been properly calibrated.

No Example Calculations

  Some reports referenced Equation 0.1 or included it in their papers.

 Some advice: Try using MathType to insert equations which look properly formatted if you don’t want to spend the time to try formatting it yourself.

Excellent reports also showed how the numbers fit into the equation to ensure the reader could repeat the test and calculations if necessary.

No mention of assumptions

 Excellent reports mentioned the assumptions made in the experiment:  “For the purpose of this experiment, we assume there is little to no interference from an outside light source.”  “Here, we assume that since we have tested two separate wavelength blockers near different ends of the spectrum, that the spectrometer is properly calibrated for all wavelengths in the visible spectrum.”

No mention of validity

 Excellent reports mentioned the validity of the experiment:  “However, because the Spectrometers could go out at any time, it is important that they are tested regularly. But, at the time of testing they were adjusted to perform in an accurate manner.”  “This experiment is relatively simple. There are few areas where there is any allowance for human error, and there are minimal chances for technological error; the consistency and correctness of the experiment’s results show that no error was made.”