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File:  [LON-CAPA] / loncom / html / adm / help / tex / Significant_Figures.tex
Revision 1.7: download - view: text, annotated - select for diffs
Mon Mar 17 04:24:56 2014 UTC (10 years, 5 months ago) by lira
Branches: MAIN
CVS tags: version_2_12_X, version_2_11_X, version_2_11_5_msu, version_2_11_5, version_2_11_4_uiuc, version_2_11_4_msu, version_2_11_4, version_2_11_3_uiuc, version_2_11_3_msu, version_2_11_3, version_2_11_2_uiuc, version_2_11_2_msu, version_2_11_2_educog, version_2_11_2, version_2_11_1, version_2_11_0_RC3, version_2_11_0, HEAD
adding description of options for sig figures, and suggestions to minimize student frustration. Minor wording/structural changes.

    1: \label{Significant_Figures}
    2: A \textbf{significant figures} specification is an optional setting that 
    3: tells LON-CAPA how many significant
    4: figures there are required for the answer, as either a single number, e.g. 3, or a range of
    5: acceptable values, expressed as \textbf{min,max}. The significant figures field can be omitted if you do 
    6: not want to constrain the number of significant digits in the student answers.
    7: 
    8: The system will check to
    9: ensure that the student's answer contains the required significant digits,
   10: useful in many scientific calculations. For example, if the computer answer is {}``1.3'',
   11: and the problem requests three significant digits, specified by (entered without quotes) 
   12: {}``3'',  the system will require the students to type {}``1.30'',
   13: even though numerically, {}``1.3'' and {}``1.30'' are the same. A significant
   14: figure specification of (entered without quotes) {}``3,4'' means both {}``1.30'' and {}``1.300''
   15: are acceptable. 
   16: 
   17: Authors should be clear in the problem statements to tell students the required
   18: number or range of significant figures. If the student response does not contain 
   19: the correct number of significant digits, the LON-CAPA response will 
   20: tell students to increase or decrease the digits in their response, but it will not
   21: tell them how many digits to use. These responses do not use up
   22: the number of trials, but such responses are frustrating for students. If you would like to ensure
   23: that at least three significant digits are used, then a specification such as 3,15
   24: ensures at least three digits are used, but will quietly accept up to 15.
   25: 
   26: Note that care must be used when using formatted computer answers together with 
   27: a significant digit specification.
   28: You must ensure that the formatted answer provides enough significant digits.
   29: To test the formatted answer, LON-CAPA converts the computer answer,
   30: as generated in the script block, according to the
   31: format attribute in the numericalresponse tag, e.g. 3f.
   32: Then LON-CAPA separately applies that number of significant
   33: figures to the computer answer, and if that result
   34: falls outside the range specified in the significant digit parameter, 
   35: it "grades" the computer answer as SIG\_FAIL (i.e., not correct). 
   36: It is a good idea to use the problem testing environment to test plenty of different
   37: randomizations to make sure that your format and sig digits parameters are compatible.
   38: This helps ensure that the formatted answer has enough significant digits.
   39:
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