learning sql with a computerized tutor (centered on sql-tutor) antonija mitrovic (university of...
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Learning SQL with a Computerized Tutor (Centered on SQL-Tutor)
Antonija Mitrovic(University of Canterbury)
Presented by Danielle H. Lee
Agenda
Problem regarding to learning SQL Purpose of SQL-Tutor System Architecture of SQL-Tutor Evaluation of SQL-Tutor
Problem regarding to learning SQL Burden of having to memorize database schemas
(incorrect table or attribute names) Misconceptions in student’s understanding of the
elements of SQL and the relational data model in general
Not easy to learn SQL directly by working with a DBMS Inadequacy of feedback from a RDBMS
Example (in Ingres): E_USOB63 line 1, the columns in the SELECT clause must be contained in the GROUP BY clause.
Inability of a RDBMS to deal with semantic errors
Research By the Univ. of Canterbury
DatabasePlace Web portal for database related lectures. SQL-tutor: teaches the SQL database query la
nguage NORMIT: data normalization tutor ER-tutor: teaches database design using the E
ntity-Relationship data model Constraint-based tutors
Automated Tutoring System The School of Computing, Dublin City University Developed for an online course name ‘the introduction to
databases’ To Provide a certain level advice and guide by using
feedback, assessment, and personalized guidance Limited the contents to the SQL SELECT sentence.
The most fundamental of the SQL Simple but having the capacity to become quite complex
There are correction model and pedagogical model. Correction model: Multi-level error categorization scheme
according to three aspects (from, where, select) Pedagogical model: analyses the information stored by the
student’s answers, it provides feedback, assessment, and guidance
Purpose of Project
Personalized ITS for Database Courses Personalized tutoring system for learning SQL To adapt SQL-tutor technology for use with a
different audience and to explore some ways to maximize the educational value for every student.
Exploration of personalized guidance technology based on the ideas of adaptive hypermedia
Purpose of SQL-Tutor system To explore and extend constraint based modeling Problem-solving environment intended to
complement classroom instruction. Problem sets with nine levels of complexity
defined by a human expert Students have a assigned educational level and
the level is updated by observing the student’s behavior. Novice, intermediate, or experienced
System Demo
http://ictg.cosc.canterbury.ac.nz:8000/sql-tutor/login
Architecture of SQL-Tutor
StudentModules
Constraints
Databases,Problems,Solutions
CBM
Pedagogicalmodule
Interface
StudentStudent
Constraint-based model (contd.) Ohlsson’s theory of learning from errors (1996)
Error recognition Error correction
Conceptual domain knowledge is represented in terms of over 500 constraints
Constraints define equivalence classes of problem states Equivalence class triggers the same instructional action A student’s solution is matched to constraints to identify any t
hat are violated. Neutral with respect to the pedagogy and knowledge domain
Constraint-based model
Example: specifying the SELECT clause of a SQL query cannot be empty
(p 2“The SELECT clause is a mandatory one. Specify the attributes/expressions to retrieve from the database.”(not (null (select-clause ss)))“SELECT”)
Unique No.
Instructional Message
Part of the constraint
Evaluation Computer Science students, Univ. of Canterbury Three experiments for evaluation
First (April 1998): to evaluation how well CBM supports student learning and to evaluate the interface and constraint base of SQL-Tutor Subject No: 20
Second (May 1999): to evaluate the effectiveness of various types of feedback in the system Subject No: 33
Third (October 1999): to evaluate the advanced pedagogical agent (no explanation)
Results of subjective evaluation
Mastery of constraints
The degree of mastery of a given constraint is a function of the amount of practice on that constraint
Measured the number of occasions relevant to each constraint and calculate the probability of violating a given constraint.
Evaluation results of learning effects
Result of first experiment
Group Mean Std Dev.
Experimental 82.75 8.76
Control 71.23 17.56
Total 76.24 15.39
Kinds of feedback
Positive/negative feedback Error flag Hint All errors Partial solution Complete solution
Result of second experiment (contd.)
Result of second experiment
CBM-based general feedback is superior to offering a correct solution.
Among six feedbacks, the initial learning rate is highest for all errors (0.44) and error flag (0.40), closely followed by positive/negative (0.29) and hint (0.26). The learning rate for partial (0.15) and full solution (0.13) are low.
Thank you