PHIL 230 Introduction to Formal Logic

Homework and Grades
Spring, 2012

Doing homework is the best way to earn a good grade

• Only those who practice working problems can expect to pass.
  In this course, studentsdevelop skills by practicing them. You cannot get these skills just by watching someone else use them, any more than you can become a good tennis player just by watching the pros without getting out on the court. You cannot gain these skills by cramming just before a test.
• For exercises that can be done on the computer, take advantage of immediate feedback provided by the software.
• Grades tend to be correlated with the number of homework problems solved.
  Grade distributions are shown for students in my sections of PHIL 230 since Spring, 2009. In a surprising coincidence, these included a total of 230 students. Students are grouped by the percentage of homework solutions they submitted. Dividing lines between groups are drawn in two different ways in the two tables. Both show a high percentage of A's and B's among students who submitted numerous solutions, and a high failure rate among students who submitted few or no solutions.

  Table 1: Each group includes about 20% of the students.

  % of assigned exercises submitted	% of students earning course grades in each range
  	A	B	C	D	F or NC
  68% to 100% of assigned exercises (19% of students)	55%	23%	14%	9%	0%
  42% to 67% of assigned exercises (20% of students)	15%	24%	26%	20%	15%
  19% to 40% of assigned exercises (20% students)	4%	11%	31%	13%	40%
  1% to 18% of assigned exercises (20% of students)	0%	4%	6%	6%	83%
  zero assigned exercises (21% of students)	0%	4%	2%	4%	90 %

  Table 2:

  Here division is not into groups of 20% of students, but intervals of 20% of assigned homework exercises. Each group includes students whose number of homework submissions fall within that range. There is one extra group: students who submitted no solutions at all.

  % of assigned exercises submitted	% of students earning course grades in each range
  	A	B	C	D	F or NC
  81% to 100% of assigned exercises (13% of students)	68%	13%	10%	10%	0%
  61% to 80% of assigned exercises (13% of studnets)	19%	45%	26%	10%	0%
  41% to 60% of assigned exercises (13% of students)	14%	11%	25%	25%	25%
  21% to 40% of assigned exercises (18% of students)	5%	13%	36%	13%	33%
  1% to 19% of assigned exercises (21% of students)	0%	4%	6%	8%	83%
  none ofthe assigned exercises (21% of students))	0%	4%	2%	4%	90%

Two sources of homework exercises

Textbook exercises: Most homework exercises are in the textbook. Many of these exercises require you to open a corresponding file on the accompanying CD.

Handbook exercises: Some exercise numbers begin with 'H' in the schedule of assignments. The instructions and questions for these are in the course handbook, and the exercise files can be downloaded from corresponding the links in the handbook exercise list. To download the file for a particular exercise:

In Firefox	While holding down the ‘alt/option’, just click on the exercise file. To save file somewhere other than your default location for downloads, hold down ‘Control’ instead of ‘alt/option’, choose ‘Save as ...’ in the pulldown menu, choose your location, and select ‘All files’ in the ‘Save as’ pulldown menu before clicking the ‘Save’ button.
In Safari	While holding down the ‘control’ key, click on the exercise file and choose ‘Download linked file as ...’, but do not change the file name. (Names should end with ‘.sen’ for sentence files, ‘.tt’ for truth table files, and ‘.prf’ for proof files.) Safari may add ‘.html’ or ‘.txt’ at the end of the file name. If so, the extra extension must be deleted before opening the file.
In Explorer	Not recommended because it creates problems with the hidden extensions that indicate file type.
In Chrome	While holding down the ‘alt/option’ key, click on exercise file and choose ‘Save link target as …’ from the pull-down menu. If you get gibberish or code when you open the file, try following the instructions for Firefox. (I have not had the opportunity to download any of these files using Chrome, but am relying on what students have told me about it. If you have problems downloading the files, I recommend using Firefox or Safari, since I have tested those instructions.)

Download instructions are also given above the calendar in the schedule of assignments.

Handing in homework

Exercises in the textbook are tagged to indicate whether solutions can be submitted to the GradeGrinder by use of the ‘Submit’ application (on the CD accompanying the text), can only be done on paper, or depend on features of the problem that the student must determine. All homework assigned for credit is to be submitted to the GradeGrinder.

To ensure that the GradeGrinder can interpret your solutions, be careful to name your solution files exactly as instructed in the text or handbook.

Earning credit for homework

• Exercises marked by asterisks (*) are required and count directly toward the course grade.
• Numerous other exercises are assigned for practice but need not be submitted. Solutions for problems not counting toward the grade can be submitted to the GradeGrinder web site for feedback, but that is optional. Solutions for exercises without ‘*’ will not add points to the homework component of your grade. However, you can expect that the practice you get by doing them will improve your performance on graded work. Whether you choose to submit these or not, you should do enough of them to feel confident of the skills they use.
• Exercises are listed with readings they cover. but need not be turned in by that date. Try some by the date listed, and ask questions in class. Discussion of each problem set is likely to extend into the next class meeting.
• Solutions to required (*) exercises are due at 11:59 PM 4 days after the date on which the exercises are lsted, with one exception: the due date is the date of the test covering the material if that is fewer than 4 days later than the date listed.
  • Exercises listed for a Tuesday should be submitted by Saturday night.
    Exercises listed for a Thursday should be submitted by Monday night.
  • Credit will be reduced for submissions 1 to 5 days after the due date, with the restriction that solutions due before a test must be submitted by the date of that test to earn credit.
  • Beyond the 4-day mark or the relevant test (whichever comes first), no credit will be given.
• Solutions with errors earn partial credit. Solutions with errors may be revised and submitted to improve the grade.
  A corrected solution turned in by the date of the corresponding test will earn points based on the date of submission of your first serious attempt at a solution. Thus full credit may be earned for subsequent corrections if the first attempt is submitted by the due date.

No extra credit

There will be no extra credit. The only things for which it would be reasonable to earn course credit are the regular assignments and tests given in the course.

Homework credit policies are subject to change

These policies may change, particularly if submissions are too few in number or are often late.

Last modified March 7, 2012.