version 1.6, 2013/09/09 20:57:01
|
version 1.7, 2014/03/17 04:24:56
|
Line 1
|
Line 1
|
\label{Significant_Figures} |
\label{Significant_Figures} |
A \textbf{significant figures} specification tells the system how many significant |
A \textbf{significant figures} specification is an optional setting that |
figures there are in the problem, as either a single number, e.g. 3, or a range of |
tells LON-CAPA how many significant |
acceptable values, expressed as \textbf{min,max}. The system will check to |
figures there are required for the answer, as either a single number, e.g. 3, or a range of |
make sure that the student's answer contains this many significant digits, |
acceptable values, expressed as \textbf{min,max}. The significant figures field can be omitted if you do |
|
not want to constrain the number of significant digits in the student answers. |
|
|
|
The system will check to |
|
ensure that the student's answer contains the required significant digits, |
useful in many scientific calculations. For example, if the computer answer is {}``1.3'', |
useful in many scientific calculations. For example, if the computer answer is {}``1.3'', |
and the problem requests three significant digits, specified by (entered without quotes) |
and the problem requests three significant digits, specified by (entered without quotes) |
{}``3'', the system will require the students to type {}``1.30'', |
{}``3'', the system will require the students to type {}``1.30'', |
even though numerically, {}``1.3'' and {}``1.30'' are the same. A significant |
even though numerically, {}``1.3'' and {}``1.30'' are the same. A significant |
figure specification of (entered without quotes) {}``3,4'' means both {}``1.30'' and {}``1.300'' |
figure specification of (entered without quotes) {}``3,4'' means both {}``1.30'' and {}``1.300'' |
are acceptable. The significant figures field can be omitted if you do |
are acceptable. |
not want to constrain the number of significant digits in the student answers. |
|
|
Authors should be clear in the problem statements to tell students the required |
|
number or range of significant figures. If the student response does not contain |
|
the correct number of significant digits, the LON-CAPA response will |
|
tell students to increase or decrease the digits in their response, but it will not |
|
tell them how many digits to use. These responses do not use up |
|
the number of trials, but such responses are frustrating for students. If you would like to ensure |
|
that at least three significant digits are used, then a specification such as 3,15 |
|
ensures at least three digits are used, but will quietly accept up to 15. |
|
|
Note that care must be used when generating and formating computer answers. |
Note that care must be used when using formatted computer answers together with |
You must assure that the specified answer format provides for enough significant digits. |
a significant digit specification. |
|
You must ensure that the formatted answer provides enough significant digits. |
To test the formatted answer, LON-CAPA converts the computer answer, |
To test the formatted answer, LON-CAPA converts the computer answer, |
as generated in the script block, according to the |
as generated in the script block, according to the |
format attribute in the numericalresponse tag. |
format attribute in the numericalresponse tag, e.g. 3f. |
Then LON-CAPA separately applies that number of significant |
Then LON-CAPA separately applies that number of significant |
figures to the computer answer, and if that result |
figures to the computer answer, and if that result |
falls outside the range specified in the significant digit parameter, |
falls outside the range specified in the significant digit parameter, |
it "grades" the computer answer as SIG\_FAIL (i.e., not correct). This helps assure |
it "grades" the computer answer as SIG\_FAIL (i.e., not correct). |
that you have enough significant digits in the formatted answers you display to the students. |
|
It is a good idea to use the problem testing environment to test plenty of different |
It is a good idea to use the problem testing environment to test plenty of different |
randomizations to make sure that your format and sig digits parameters are compatible. |
randomizations to make sure that your format and sig digits parameters are compatible. |
|
This helps ensure that the formatted answer has enough significant digits. |
|
|