WAEC SSCE - Data Processing - 2018 (Essay and Test of Practical Work)

Answer Details

This question tests knowledge of data models and approaches to data modelling.

(a)(i) Data model. A data model is a way of describing and organising how data is structured, stored and related in a database, defining the data elements, their attributes and the relationships between them.

(a)(ii) Three types of data model.

• Hierarchical model: data is organised in a tree-like, parent-to-child structure.
• Network model: data records are linked, allowing a child to have several parents (many-to-many links).
• Relational model: data is stored in tables (relations) of rows and columns, linked by common fields.

(The object-oriented model is another acceptable type.)

(b)(i) Three approaches to data modelling.

• Conceptual data modelling (high-level, entity/relationship view).
• Logical data modelling (detailed structure independent of any DBMS).
• Physical data modelling (how the data is actually stored in a particular DBMS).

(b)(ii) Explanation of one approach. Conceptual data modelling gives a high-level, technology-independent picture of the data. It identifies the main entities (such as Student, Course), their key attributes, and the relationships between them, usually drawn as an entity-relationship diagram. It focuses on what data the organisation needs and how items relate, not on how the data will physically be stored, so it is used early in design to agree the requirements with users.

Examination reminder: do not confuse the types of data model (hierarchical, network, relational) with the levels/approaches of modelling (conceptual, logical, physical); this question asks for both.

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This question tests choice of application software, a document feature, information security, and two general computing terms.

(a)(i) Most suitable application software. A word processor (for example Microsoft Word) is best for typing and formatting the confidential report.

(a)(ii) Feature to insert "CONFIDENTIAL" diagonally in the background of every page. The Watermark feature (a diagonal text watermark) places the faint word across the background of every page.

(a)(iii) One measure to keep the soft copy confidential. Protect the file with a password (encrypt the document) so that only authorised persons can open it. (Restricting access rights or storing it in a secure/encrypted folder is also acceptable.)

(b) Terms.

• (i) Icon: a small graphical picture or symbol on the screen that represents a program, file, folder or command, which the user clicks to select or open it.
• (ii) Browser: a browser (web browser) is application software used to access, retrieve and display web pages and other information from the Internet, for example Google Chrome or Mozilla Firefox.

Examination reminder: the diagonal faint text behind every page is specifically a watermark, a word-processor feature; do not confuse it with a header, footer or text box.

Answer Details

(a) Creating the Query By Example (QBE) in Microsoft Access, given that the Customer table already exists.

1. Open the database and click the Create tab.
2. Select Query Design.
3. In the Show Table box, add the table tblCustomer to the QBE (query design) interface, then close the box.
4. From the field list, select the field Last Name into the design grid.
5. Select the field First Name into the design grid.
6. Select the field Town into the design grid.
7. In the Criteria row under the Last Name field, type John.
8. Tick all the check boxes in the Show row under the Last Name, First Name and Town fields so that the three fields are displayed in the result.
9. Click Run to execute the query, then save it with a suitable name.

(b) Generating the SQL statement for the query in 4(a).

Use any one of the following:

• Right-click on the Query (QBE) interface and select SQL View; or
• From Design View, click View and select SQL View; or
• Click on the SQL button at the bottom right corner of the window.

Access then displays the equivalent SQL for the query, of the form:

SELECT [Last Name], [First Name], Town FROM tblCustomer WHERE [Last Name] = 'John';

Answer Details

This question tests printing a page range on a multi-printer system, dealing with pop-ups, presentation software, and types of network.

(a) Print the first five pages on a computer with two printers.

1. Open the document and click File, then Print (or press Ctrl + P) to open the Print dialog box.
2. In the Printer/Name list, select the particular printer you want to use (since two are installed).
3. Under Page range, choose Pages and type 1-5.
4. Set the number of copies, then click Print/OK.

(b) The disturbing pop-up.

• (i) Possible cause of the pop-up: pop-up advertisements or adware/malware on the computer (or pop-ups triggered while browsing certain websites).
• (ii) Possible cause of the element (program) producing it: adware or a virus was installed, often bundled with free downloaded software, or was picked up from visiting unsafe websites.
• (iii) Measure to stop it recurring: install and run up-to-date antivirus/anti-adware software to remove the adware, and turn on the browser's pop-up blocker (and avoid untrusted downloads/sites).

(c) Mr Aneke's address in an auditorium.

• (i) Suitable application package: a presentation package such as Microsoft PowerPoint.
• (ii) Output device to send the speech notes to a large screen: a multimedia (data) projector.

(d) Two types of computer network: LAN (Local Area Network) and WAN (Wide Area Network) (MAN and PAN are also acceptable).

Examination reminder: to print a range, choose "Pages" and type 1-5 (a hyphen means "through"); and remember to pick the correct printer first when more than one is installed.