++ rating: 5
++ time: under 2 hours
++ difficulty: 5
++ learned: 5
++ anoncomments: The questions seemed out of the blue. My introductory astronomy students (non-science majors) had no clue how to answer them. 
++ (corrected) Grammatical error:
Once the pattern of the lines of a particular element have been observed in the laboratory"   Should be "has been"
++Students had the following problems:
 ++ (corrected) They didn't realize the solar spectrum is different for the first part and the link labeled "Measure". They went back to the first and couldn't figure out which lines to measure (1 - 13). Why do there have to be two spectra?
 ++ (corrected) Even though they just calculated a scale factor in nanometers per pixel, then were asked to convert pixels to nanometers, they couldn't understand what to do. It would be so simple to say "multiply" in Part B, step 4.
 ++ (corrected) If they pick any line but K, in step 5, they need to not just add, but sometimes subtract, depending on where their reference line is in relation to the unidentified line.
 ++ At the end of the lab, they didn't know what they just did, even though they followed all the steps.
 ++ I liked that anyone could do this lab with no set-up.