25.0 COMPUTER STUDIES (451)
From the inception of revised secondary curriculum in the year 2002, the subject Computer Studies has been
examined five times in the years 2006, 2007, 2008, 2009 and 2010 respectively.
The subject is examined in three papers:
26.1 CANDIDATES GENERAL PERFORMANCE
The table below shows performance in Computer Studies in the years 2007, 2008, 2009 and 2010.
Table 31: Candidates Overall Performance in Computer Studies for the last three years.
The following are the observation:
25.1.1 There is a dramatic increase in candidature in the subject from 4,732 in the year 2007 to 7,045 in year
2010. This representing 48.9% and 15.2% from 2009 to 2010
25.1.2 Overall performance in the subject increased from a mean of 96.34 in the year 2009 to 96.34th the year
25.1.3 Performance in paper 1 (451/1) increased from a mean of 45.41 in the year 2009 tc a mean of 51.98 in the year 2010, representing a 14.47% increase.
25.1.4 Performance in both the practical paper (451/2) increased from a mean of 50.93 in the year 2009 to a mean of 59.83 in the year 2010, representing a 17.47% increase.
Questions which were poorly performed in the 2010 examinations are briefly discussed below.
25.2 PAPER 1 (451/1)
List four activities carried out by a data processing system.
WeaknessesStudents were listings the stages of data processing cycle
Advice to Teachers
Teachers should emphasize the distinction between the activities in SDLC and the data processing stages
Explain why an intranet is a more secure way to share files within an organisation compared to the internet.
Intranet is a company's internal network to which outsiders cannot get access to while Internet allows outsiders to access company network if proper security measures are not implemented.
Some candidates could not relate intranet security in terms of number of users
Study the pseudo code below and determine its output.
1(a) T =0
2(a) M =M+T
3. Repeat step 2 while K< 3
4. Write M, T
Learners were expected to generate the following list of output
Candidates showed inability to execute the number of times the pseudo code ioop executes and therefore producing wrong output.
Copyright laws are laws granting authors the exclusive privilege to produce, distribute, perform or display their creative works. It is a legal framework for protecting the works such as book publishing, motion-picture production and recording.
State two challenges that are posed to these laws by JCT.
- Easy of communication.
- Easy of duplication
- Enforcing is still a problem e.g. officers are not computer literate.
- Lack of capacity for people enforcing the law
The question was poorly attempted. Majority of the candidates were unable to give challenges posed to copyright laws by ICT
Advice to the teacher
The teachers are expected to make emphasize on this area. There are many imported reference materials which exhaustively cover this topical area.
(a) Machine language programs are more difficult to write than high-level language programs. State two reasons for this.
(b) In order to process examination results of students in a school, their names, index numbers and scores in 11 subjects are required. The average score for each student is then determined and a grade assigned. This process is repeated for all 40 students in a class.
Draw a flowchart to:
Read a student's name, index number and the scores in all the subjects.
Determine the student's average score.
Assign a grade to the student depending on the average score as follows:
Display the student's name, index number, average score and the grade.
Repeat the above steps for all the students in the class.
(c) Below is a list of program segments in different generations of programming languages. Identify the language for each.
105 SUB 40 ADD 20
(ii) 10000110 1011110101111000 0001100
(iii) For x: = 1 to 10 do Write (x);
It is time consuming to develop.
It is easy to make mistakes because only 0's and l's are used.
Program written for one computer model may not run on another computer model.
Expected flow chart is as shown
Generation of programming languages:
(i) Second generation
(ii) First generation
(iii) Third generation
Most students were unable to use appropriate flow charting tools. They were also unable to conceptualise the looping structure in the narrative.
Advice to the teacher
Flow charting concept should be emphasised when teaching by using real life problems. Learners to be exposed to more exercises on the same.
(a) Using ones complement, convert the decimal number 9 into a 6-bit binary number
(b) (i) State three standard coding schemes used in data representation.
(H) In a certain coding scheme, each character occupies 7 bits. Letters of the alphabet are assigned consecutive codes. If letter N is represented by 1010010; what is the representation of letter A in this coding scheme
(c) Using twos complement, show how the arithmetic below would be carried out on a 8-bit computer system.
The candidates had difficulty in representing letters character in its equivalent binary notation implying that they had no idea on how characters are represented using the four coding schemes as required in the syllabus namely; ASCII, BCD, EBCDIC, Extended ASCII
25.3 PAPER 2 (451/2)
Mr Kiprop Onyango owns houses for rent. Table 1 below is a record of his tenants rent payments.
(a) Create a database file that can be used to store the above data. Name the file �Rent'.
(b) Create two tables, one to store tenant details and another to store tenant rent payments. Name the tables �Tenants and �Payments respectively.
(c) Create a relationship between the two tables.
(d) Design a form to be used to enter data into each of the two tables
(e) Enter the information given into the two tables.
(0 Create a report showing the amount Mr. Onyango received from each tenant, the total for each month and the total amount he received over the three months. The report should be titled �Rent Income'. Save the report as Income.
(g) (i) Create a query named �Statement' to extract Malols records of rent payment.
(ii) Create a report named �Tenant Statement' showing Malols rent payment history. The report should be titled Tenant Statement'.
(h) Print the two tables and the two reports.
Expected response(a) Creating a database
Correct database name
(b) Creation of the two tables
Each table �/2 mark
Primary key (1 table)
Fields (first table)
a 3 fields
Fields for the 2nd table
- Correct relationship
- Choosing correct table
- Enforcing the relationship
(d) Creating the two forms
- Existence of fields
- Providing name to each form
(e) Each tenant record (Form) �/ x 6
records Each payment record (Form) � x 12 records
(f) Presence of report
Appearance correct (fields)
- Amount Use of functions
- Sum January, February, March
- Grand total
Report naming and saving
(g) (i) Presence of correct query
Presence of fields (Name, Amount, Month) in the query Correct criteria
Data source (query) Name of report (saving) Title of report
(h) Printing: Candidates expected to print:
- 2 tables
- 2 reports
Candidates were not keen to name the database using the name provided, they use default names as supplied by the application.
Some candidates were unable to split the table provided into two distinct entities, showing clearly that they lacked the basic knowledge of normalisation.
Some candidates created forms that were not related to the table structure
There were cases of wrong data entry, indicated that learners were not keen on their work or they lacked basic keyboard skills.
Creating report with summaries proved to be an uphill task for some many candidates indicating that they lacked the basic concepts on the creation of summaries using the inbuilt functions as provided for by the application.
Some learners were unable to produce the required hard copies of their work, indicating that they lacked concepts of printing.
Advice to Teachers
The teachers should introduce basic concepts of normalisation up to the First Normal Form (1NF) without taking the candidates through the complexities of normalisation. The learners should be able to appreciate the need to have tables split.
Schools should ensure that learners are exposed to hardcopy output devices, which include printers and their accompanying accessories so that learners can perform some of the required task with speed and accuracy.
What it takes