Actas JP2011 - Universidad de La Laguna

Actas XXII Jornadas de Paralelismo (JP2011) , La Laguna, Tenerife, 7-9 septiembre 2011teacher can also restrict the visibility of the resultsby controlling if the automatic feedback will beshown to the student immediately aftersubmission, if it will be delayed until a given dateor if it will remain totally hidden.although one of them must be marked as thedefault.Submissions: A submission instance is defined foreach pair team/practical assignment. It embracesthe file(s) submitted by a team for eachassignment and all report files and statusinformation generated after the verification of thesubmitted labwork. The teacher can inspect allthese elements to obtain an overall picture of thestudents’ progress. It is also possible to manuallyadd a short feedback message to the student.Other administrative functionalities, such as statisticreports (through the options course at a glance andstatistics), the management of the student teams(maximum number of members, deadline for its setup), and the updating of the Moodle gradebook withthe activity scores, are accessed through the sidecontrol block (Figure 1).(a)Figure 3: Teacher view for creating and managing the testers.(b)Figure 2: Activity views for students (a) and teachers (b).Testers: This feature is used by the verification engineto check if a submitted labwork fulfills thespecifications. It is possible to add new testers orto edit previously created ones (Figure 3).Moreover, teachers can share testers or reuse theones defined in preceding courses. Testers may beenabled or disabled by the teacher. If disabled,they will not be applied by the verification engine.An interesting feature is that several testers maybe defined for the same practical assignment,IV. VERIFICATION ENGINE FOR MATLABThe automatic verification engine is in the core of theCTPracticals module. Students submit the requestedMatlab source files (.m) as one .zip file. The verificationengine uncompresses the submission and then runs theMatlab sources. According to the execution outputs,which are compared to a reference correct output, thestatus result of verification (right/wrong) is generatedtogether with the corresponding feedback information.The verification process takes place in three phases [9]described in Table I. To extend the CTPracticalsfunctionality to Matlab labworks, changes werenecessary in the first two phases.At the time of submission, the verification process isautomatically triggered using the default tester.Additionally, it can be manually started by the teacher inbatch mode, which may be useful when some changeshave been introduced after submitting or if severaltesters have been defined for a same assignment. Apractical assignment can be resubmitted an unlimitednumber of times until the deadline expires. The feedbackinformation includes not only the result (right/wrong)but also possible format errors in sources (static analysisJP2011-585