Functionalities

Functionalities

Currently LEARN-SQL allows to learn and to evaluate the correctness of the following types of relational database exercices

  • SQL queries
  • SQL insertions, updates and deletes
  • SQL creation of tables, views and sequences
  • Logical design
  • Normalization
  • Relational algebra
  • Stored procedures
  • Triggers
  • JDBC applications
  • Multidimensional operations
  • Optimization - Materialized views
  • Optimization - Indexes
  • Query cost estimation

Concepts

An Item is a question that is defined by a teacher by means of the Authoring Tool (AT). Once an item is defined it can be included in a Remote Test by means of the Remote Test Module (RTM). Students resolve the remote test, and their responses are sent to one Scorer web service to be evaluated and corrected.

One item is addressed to asses one or more Thematics (union, join, etc...), uses a database Schema, and belongs to a certain Kind of items (selects, inserts/updates/deletes, creates, relational algebra, etc.). One item has also associated several Experiments, which will be used to assess a student response of the item, and one or more Scorers that may execute and correct it.

The main attributes of an item are:
•    The title, which identifies the item.
•    The link to an attached file, which have extra information that will be offered to the students about the item.
•    The statement, which describes what is required to do to the student.
•    The difficulty of solving the item.
•    The author, which will be one of the teachers that are users of the AT.
•    The kind of response, which states how the author states the response. Which may be one text response introduced to the AT, one file response, or an URL+username+password where the response may be find.
•    The initialization sentences, which have to be executed by the scorer before correcting the item.
•    The cleaning sentences, which have to be executed by the scorer after correcting the item.
•    Our response to the item, which is a correct response to the stated item.
•    The assessed Thematics, the Schema used, and the Kind to which belong.
•    The Scorers, which are the web services that may execute and correct the item.
•    The Experiments, which are different input states of the database that correspond to different circumstances on which the item may be executed and that will help in the correction of the item.

One item may be executed by means of one or more Scorer. Each scorer may execute and correct items corresponding to one or more Kind. One Scorer needs Experiments for executing or correcting an item. These experiments allow obtaining the output result of the experiment for the correct response to the item, and the output result of the experiment for the response of an student. The attributes for each experiment are:
•    The name of the experiment.
•    The description of the experiment
•    The error message, which have to be displayed during the correction of an item, if the response of the student does not pass the experiment.
•    The initialization sentences, which have to be executed before execute or correct the response of the item.
•    The input sentences, which are necessary to execute, for some Kind of items, for executing the response of the item. 
•    The cleaning sentences, which have to be executed after execute or correct the response of one item.
•    The output result, which is the result obtained by executing our response to the item, considering the experiment.
•    The checks that have to be done, for some Kind of items, for executing and correcting the student response.
One Check consists on a query to know the state of the database just after the execution of the correct response to the item, and after the correction of the response of an student for the experiment for which the check is defined.
•    The name of the check.
•    The description of the check.
•    The error message that is shown to the student if his/her response does not pass the check.
•    The input sentences, which will be executed to test if the student response pass the check.
•    The output result, which is the result obtained by executing the check just after the execution of our response to the item, considering the experiment to which this check corresponds.

As a summary the correction of a response of an student for an item consists on: comparing the output results of each Experiment, and each Check related to the item, obtained considering the student response with the output results obtained during the definition of the item considering the teacher response.