Semi-automatic assessment of basic SQL statements

Learning and assessing the Structured Query Language (SQL) is an important step in developing students' database skills. However, due to the increasing numbers of students learning SQL, assessing and providing detailed feedback to students' work can be time consuming and prone to errors. The main purpose of this research is to reduce or remove as many of the repetitive tasks in any phase of the assessment process of SQL statements as possible to achieve the consistency of marking and feedback on SQL answers.

This research examines existing SQL assessment tools and their limitations by testing them on SQL questions, where the results reveal that students must attaint essential skills to be able to formulate basic SQL queries. This is because formulating SQL statements requires practice and effort by students. In addition, the standard steps adopted in many SQL assessment tools were found to be insufficient in successfully assessing our sample of exam scripts. The analysis of the outcomes identified several ways of solving the same query and the categories of errors based on the common student mistakes in SQL statements.

Based on this, this research proposes a semi-automated assessment approach as a solution to improve students’ SQL formulation process, ensure the consistency of SQL grading and the feedback generated during the marking process. The semi-automatic marking method utilities both the Case-Based Reasoning (CBR) system and Rule-Based Reasoning (RBR) system methodologies. The approach aims to reduce the workload of marking tasks by reducing or removing as many of the repetitive tasks in any phase of the marking process of SQL statements as possible. It also targets the improvement of feedback dimensions that can be given to students.

In addition, the research implemented a prototype of the SQL assessment framework which supports the process of the semi-automated assessment approach. The prototype aims to enhance the SQL formulation process for students and minimise the required human effort for assessing and evaluating SQL statements. Furthermore, it aims to provide timely, individual and detailed feedback to the students. The new prototype tool allows students to formulate SQL statements using the point-and-click approach by using the SQL Formulation Editor

(SQL-FE). It also aims to minimise the required human effort for assessing and evaluating SQL statements through the use of the SQL Marking Editor (SQL-ME).

To ensure the effectiveness of the SQL-FE tool, the research conducted two studies which compared the newly implemented tool with the paper-based manual method in the first study (pilot study), and with the SQL Management Studio tool in the second study (full experiment).

The results provided reasonable evidence that using SQL-FE can have a beneficial effect on formulating SQL statements and improve students’ SQL learning. The results also showed that students were able to solve and formulate the SQL query on time and their performance showed significant improvement.

The research also carried out an experiment to examine the viability of the SQL Marking Editor by testing the SQL partial marking, grouping of identical SQL statements, and the resulting marking process after applying the generic marking rules. The experimental results presented demonstrated that the newly implemented editor was able to provide consistent marking and individual feedback for all SQL parts.

This means that the main aim of this research has been fulfilled, since the workload of the lecturers has been reduced, and students’ performance in formulating SQL statements has been improved.