Dear colleagues, Regarding our last meeting, please find below extensive details regarding how to grade the first Homework for CS101. > If needed, please also find again the few slides asking these problems. ![Empty](https://ga-beacon.appspot.com/UA-38514290-1/mail/29-01-15/CS101_First_Homework?pixel) > There is a lot of details in this email, please try to read, practice and understand all of it, *if you think you need it*. --- ## What deadline? Let us try to have ALL the grades by **next Wednesday**, so we can try to give back the homework as soon as possible (on the next lab, next week), before the first Mid-Term exam. --- ## Who grades what? - I take my two groups (**A1**, **A4**: I have all the answers), - *Prof. Vipin* takes his two groups (**A2**, **B2**: he still have to collect the last answers), - *Prof. Thiyagarajan* (assisted by Prof. Kondaiah) takes two of his groups (**A3**, **B4**, still have to collect B4 tomorrow, A3 next Monday), - *Prof. Arya* and Prof. Vivek takes the last groups (**B1**, **B3**, still have to collect B1 next Monday). --- ## Marking scheme to follow Please find attached two examples of answer papers, corrected in red color by me, and scanned. I propose the following marking scheme (can be modified if you think it needs to) : - 20 total marks. - 3 marks for [Pb1](http://goo.gl/xwN89a), 6 marks for [Pb2](http://goo.gl/rIFW8p), 3 marks for [Pb3](http://goo.gl/3m6Wgl), 5 marks for [Pb4](http://goo.gl/UH6pjZ), and 2 marks for [Pb5](http://goo.gl/Wkdoq4) + 1 bonus point. > In details, I suggest this: ### [Problem 1:](http://goo.gl/xwN89a) - 1 mark for input values *x, y* - 1 mark for $x_{min} < x < x_{max}$ and $y_{min} < y < y_{max}$ - 1 mark for the good output ("Inside" or "Outside") ### [Problem 2 (the harder):](http://goo.gl/rIFW8p) - 1 mark for the good input for *x, y* - 3 marks for how to compute the equation of the line (*ax+by+c*) / the z-component of the cross product $( \mathbf{PQ} \times \mathbf{PA} ) . \mathbf{z}$ (cf. my last email for more math. details about that test) - 2 marks for the correct output regarding the sign of *ax+by+c* (if they used the equation of the line) / of the cross product (be sure to check if they did not mess up the sign and the direction, printing left when it should be right or the opposite) ### [Problem 3:](http://goo.gl/3m6Wgl) - 1 mark for computing the distance with the good math formula ($d = \sqrt{ (x-x_c)^2 + (y-y_c)^2 }$) - 2 marks if the three cases of the output are good (on the circle if $d = r$, outside if $d> r$, inside if $d < r$) ### [Problem 4:](http://goo.gl/UH6pjZ) - 2 marks for explicitly computing the 3 equations for AB, BC, CA / or computing the z-component of three different cross-product - 2 marks if they say which values have to be positive for the point to be inside the rectange - 1 mark for the good output ### [Problem 5:](http://goo.gl/Wkdoq4) - 2 marks, as you like. Basically, 2 if they did it in a way *you understand*, 0 otherwise. ### Bonus ! Finally, I suggest a last +1 point if the student did good drawings and/or a good presentation. --- ## More details about the solutions, and their respective Python programs If you need more detail about the solution, please find attached one Python program that solves each problem; or in the .zip archive file, one file for each problem. > (you should be able to execute it on your laptop, or on any on-line Python 2 interpreter, as http://repl.it/languages/Python or http://pythontutor.com/visualize.html). ### Practice your Python! For example, for the problem 1, please consult the page http://repl.it/9NX for all the problems. > Or click on these links: http://goo.gl/xwN89a for a visual demo of the execution of the program for problem 1. > http://goo.gl/rIFW8p for problem 2, or http://goo.gl/3m6Wgl for problem 3, > http://goo.gl/UH6pjZ for problem 4, and http://goo.gl/Wkdoq4 for problem 5. --- ## How / Where to input the grades? As discussed, let us try the built-in feature of Moodle for this. Please go to that page (http://www.mahindraecolecentrale.edu.in/portal/grade/report/grader/index.php?id=27) as soon as you are done grading your group(s). Then, log-in with usual id/password, select your group, and click on "Turn editing on". Finally, you can add all the grades for your group, and click on save. > - If this fails, we will go back to using a basic XL sheet. > - If you lost your ID or password, I will create a new one for you. ![Empty](https://ga-beacon.appspot.com/UA-38514290-15/mail/29-01-15/CS101_First_Homework?pixel) --- Happy grading ! -- Lilian Subject: How to grade the first CS101 Homework : marking schema and more [CS101] To: Profs. Arya, Vipin, Lilian, Thiyagarajan CC: Profs. Kondaiah, Vivek, Dhande, Didier CCi: Prof. Lilian