Letter Grade Gradebook: export, import, and history oddities

Description

With a Gradebook defined as Weighted Categories Letter Grades
and with the 5 sakaistu test users.

my setup included two categories each with one item
=============
– enter some grades of various types, with pluses and minuses.


note the history shows the grades are translated to points for storage in the db (grade translated by a lookup from the grade to value translation table, with the value returned then multiplied by the item points to get the points value.)
– export the file


note that all exported cell values are letter grades – all db stored points values have been translated to letter grades by lookup against the value range to letter grade translation table.
– edit in excel, and add/change some grades by entering a letter grade in the cell and some by entering a points value in the cell
— you can use points within the possible range for the item, as indicated in the column header, or enter points greater than the max to get an import error later.
— you can use letter grades that are not defined in the grade scale to get an import error later.
– import the updated file and note any import errors


note that points values within the possible range for the item are allowed from the import file, where they aren't allowed from the gradebook spreadsheet entry form itself. This would be necessary to support scantron and clicker import files.


note the history shows the letter grades from the file have been translated to points by looking up the grade in the grade to value translation table, and multiplying the value returned by the max item points.


note the history shows that the points values from the file have been entered directly into the gradebook, without adjustment.
– after import, all grades are shown as letter grades in the gradebook spreadsheet (the points values stored in the db are looked up in the value range to grade lookup table to determine the grade to display)

===============
now for the oddities exposed by the history records:.

if you enter grades in an excel spreadsheet for import using points, then export the gradebook and reimport it, the points value stored can be changed . E.g. a grade imported as a 70 out of 100, and stored in the db as a 70, translates to a value of 71.6666666666 when the grade is exported and reimported (history shows: Import score: '70.0'-->'71.6666666666').
– – this can change the calculated course grade in situations close to the dividing line.

if you enter a grade that translates to a long or repeating decimal, then on export and import, it will always show in the history due to a rounding/truncation difference between the lookup translations and the stored db value. E.g.history shows: Import score: '88.33333333'-->'88.3333333333' or Import score: '71.66666667'-->'71.6666666666'
– – I don't believe this is likely to change the calculated course grade.

Environment

win XP service pack 3 firefox 3.6.6

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Thomas Amsler August 5, 2010 at 12:10 PM

This is fixed via GRBK-668. Closing this issue.

Michael Wenk July 22, 2010 at 12:09 PM

r69351

Michael Wenk July 22, 2010 at 10:57 AM

I have synchronized the grading scale to be evenly distributed and we now always use the hard coded scale for final grade determination.

This is done as work for GRBK-668.

Unit testing

Thomas Amsler July 14, 2010 at 1:11 AM

The strategy is to "synchronize" all grade scale related data for letter grade based gradebooks

Thomas Amsler July 14, 2010 at 1:08 AM

Kirk,

As discussed during our phone calle, I have compiled the information about the different grade scales:

https://docs.google.com/document/edit?id=1drGBQYx6Eg7zlQQYXdmLg3dVkwtXqBPa0Tx7EkOokIk&hl=en&authkey=COW28a4I

This document provides information about the three "different" grades scales. Two are used to map percentages to letter grades and vise versa. The third one is use to map the calculated percent course grade to a letter grade.

Best,
– Thomas

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Created July 8, 2010 at 5:36 PM
Updated August 10, 2010 at 9:30 AM
Resolved July 22, 2010 at 12:09 PM