List of Common Mistakes for the 'Periodic Table' (Console-based) Assignment:

Category

Mistake

Suggested Percentage Of Assignment
(explanation here)
  Array Of Object References

30

Correctness

You don't check that any given array slot is null, in order to determine if a slot contains an element or not.

-15%
Correctness

You don't check to see if an index is within the bounds of the array.

-5%
Efficiency

(maybe correctness, too)

Your code allocates objects, but then immediately discards them by overwriting the variable with an existing reference.

(this is the classic
Element e = new Element(...);
e = existingObjRef;
mistake)

-5%
Modular design / Functional Decomposition

Since several parts of the program are functionally identical (adding an element, editing an element, etc) - you should factor your code into method(s) and re-use it, rather than duplicating the code multiple times

-10%
  Print A Single Element

10

Correctness

You code should check that the index is in the bounds of the array (where appropriate)

-3%
Correctness

You code should check that the object reference at the specified index isn't null (where appropriate)

-5%
(Failure to complete part of the assignment) If the element is not present, then your code should jumped to the 'add an element' logic -3%
  Print All Elements

10

Correctness

You code should check that the object reference at the specified index isn't null (where appropriate)

-5%
  Adding New Elements

10

(Failure to complete part of the assignment)

Your program should not allow the user to overwrite an existing element using 'Add', but it does.

-4%
Robust coding - remains correct in the face of (reasonable) future changes

You don't the existing 'user-input-validating methods' to get a valid weight

-4%
  Editing Existing Elements

10

Correctness

You code should check that the index is in the bounds of the array (where appropriate)

-3%
Correctness

You code should check that the object reference at the specified index isn't null (where appropriate)

-5%
(Failure to complete part of the assignment) If the element is not present, then your code should jumped to the 'add an element' logic -3%
Robust coding - remains correct in the face of (reasonable) future changes

You don't the existing 'user-input-validating methods' to get a valid weight

-4%
  Computer Efficiency            (Efficient use of resources, such as memory)

10

Don't create unused variables The variables r1, x, and y are unused – remove them. -1%
 Don't create unneeded local variables

For something like:
double distance = Math.Sqrt(((_centerX - x)*(_centerX - x)) + ((_centerY - y)*(_centerY - y)));
return distance;

you can instead write:
return Math.Sqrt(((_centerX - x)*(_centerX - x)) + ((_centerY - y)*(_centerY - y)));  

-1%
  Style / Presentation

10

Commenting

You didn't comment any of your code. 

-1%
Identify the author of each file

You didn't put your name, etc, at the top of EVERY  source code file, including any files given to you. (The "etc" part includes the name of this class (“Computer Science 1xx”), and the year and quarter, and the assignment number, including the revision number) 

-1%
Quality of presentation

(Make sure that what you've handed in looks good)

Code that you've commented out, because you're no longer using it, should be removed before handing in the assignment.

-1%
Horizontal Indentation Your code isn't formatted entirely consistently – in your C# file, try doing a "Select All", then under the "Edit" menu, under "Advanced", do "Format Selection" -1%
Vertical White Space Your code contains excessive numbers of blank lines in at least one place.   
  OOP-related
(OOP isn't required, nor expected, on this assignment, but sometimes students will have (and use)  prior knowledge anyways)

<NONE>

Proper encapsulation

Within your classes (for this, and future assignments) all data field, methods, properties, etc, should be marked public or private (or protected, or internal, if you choose to look those up on your own, etc) – you left this out in several places.

No points deducted, but feedback to students is good.
C# language specifics

If you're interested, look at the differences between  a class & struct – your AssignmentFunctions is a perfect example of where to use a struct (since it basically just exists to hold data)

No points deducted, but feedback to students is good.
  General Assignment Mistakes  
Submission Mistake You included the "Debug", "bin", or "obj" directories, and you shouldn't have. The assignment specifically said not to do this.

These result in point penalties, since the student has failed to complete one or more parts of the assignment, even though no particular percentage has been assigned to this category.

Submission Mistake

You didn't include the project files, please do so in the future. The assignment specifically said to do this.

 

 

Explanation of Percentages assigned:

Please note that for any given category, the total of the penalties may add up to more (or less) than the total for the category ; many of the mistakes are mutually exclusive (and since they therefore can't all apply, it's ok to add up to more than the category total), and if the student doesn't include any work in a particular category, it is suggested that you remove all points from that category (even if the individual items don't add up to the category total)

 


This document and the related materials are developed with support from Microsoft Research Computer Gaming Initiative under the Computer Gaming Curriculum in Computer Science RFP, Award Number 15871.