KCSE 2022 EXPECTED COMPUTER STUDIES — Paper 1 ANSWERS - Education in Kenya-Facts, News, Analysis and Resources

Section A (40 marks)

Answer all questions in this section

1. State the meaning of the term ligature as used in DTP. (2 marks) Combination of two letters to come up with one so as to improve legibility

(THEORY MARKSCHEME)

2. State two importance of observing computer lab rules while using the lab. (2 marks)

Ensure safety of equipment/protect equipment from damage

Start

X=0

Input T

Z=T-1

Z=1 N	is T di-	N
visible by
?	Z

Y	Y


	X=1

X=1 Y

Print T

Stop

Figure 1

Z=Z-1

Use the provided trace table to determine the output of the flowchart when each of the following numbers are input:

I. The number 3.						( 2 marks)

	X	T	Z	Is Z=1	Is T divisible by Z	Is x=1	Print T

0	3	2	N	N	–	–

0	3	1	Y	–	N	3

3 is output

1mark for trace table, 1 mark for output

	II. The number 4				(2 marks)

X	T	Z	Is Z=1	Is T divisible by Z	Is x=1	Print T

0	4	3	N	N	–	–

0	4	2	Y	Y	Y	–

Nothing is printed

(ii) State the purpose of the flowchart. (1 mark) Determine if the input number is an odd number 1 mark

17. (a) Describe each of the following internet services.

(i) World Wide Web.

Offers ways of accessing a document in several internet servers over the internet

1 @ 1 mark

(1 mark)

(ii) E learning

(1 mark)

A learning system based on formalized teaching but with help of electronic services such as the

computer and internet

1@1mark

(iii) E commerce	(1 mark)
Financial transaction/buying and selling/trading conducted over the internet.
1@1mark
(b) (i) State three ways by which negative numbers can be represented in binary number
system.	(3 marks)

By use of a sign bit

By use of one’s complement By use of two’s complement

3@1mark each

The following are data security terminologies. State the meaning of each:

I. data encryption,

Converting data from openly readable format to encoded format

(1 mark)

Converting data from plain text to cipher text

Data encoding where data can only be accessed by decoding with a person with the correct key Any 1 @ 1 mark

II. Cracking,

Breaking of computer software/system security with malicious intentions

(1 mark)

Intruding computer systems without authorization in order to gain access to them for bad/malicious/

Criminal intent.

Any 1 @ 1mark

	III. Audit trail	(1 mark)
A record of changes that have been made to a computer database/file
1@1 mark
	(iii)I. List two data processing modes	(1 mark)
	Online
	Timesharing
	Multiprocessing
	Distributed
	Batch
	Multiprocessing
	Multiprogramming
	Multitasking
	Interactive
	Real-time
First 2@ ¹/₂ mark
	© 2022 CaSPA Eldoret Diocese 451/1	Turn over

II. List two data processing methods (1mark)

Mechanical

Manual / conventional Electronic

First 2 @ ¹/₂ mark each

III. Describe one error that may occur during data processing. (1 mark)

Transcription: error occur by wrong transfer/copy of data to system

Transposition: error occur when data elements/characters positions as swapped. First 2 @ ¹/₂ mark each

Explain how each of the following stages of system development life cycle may contribute to the successful development of a new information management system.

(i) Investigation of existing system. (1 mark)

Look at current situation therefore understanding weakness of current system Enable one prepare proposals/expectations for new system

Any 1 @ 1mark

(ii) Feasibility study (1 mark)

Look at the proposed system and determine if it can succeed before commencing. (accept mention of individual feasibility studies and justifications)

Any 1@1mark

(iii) Requirements specification (1 mark) Specify what the new system must be able/should be able to do so as to enable adequate testing.

Any 1@1mark

18. (a) Other than straight change over, list two other system change over strategies that can be

used in the implementation of a new system. (1 mark)

Pilot

Phased Parallel

First 2 @ ¹/₂ mark each

(b) (i) State three differences between macro and mini computers.	(3 marks)
Micro		Mini
Are personal computers(meant for single user)	not personal (a multiuser computer)
High portability		not portable
Use single microprocessors	uses multiple processors
Small storage capacity (in GB)	Huge storage capacity (TB)
Lower speed compared to mini computer	higher speed compared to micro computer
Less powerful compared to mini computer	more powerful compared to micro computer
3@1 mark each
(ii)	I. State the meaning of the term ICT Career.	(1 mark)

An occupation undertaken in ICT for a significant period of a person’s lifetime with opportunity for growth/progress 1@1 mark

II Other than computer technician and computer engineer, name two other career

opportunities in ICT. (1 mark)

Computer operator Programmer

Software engineer

Database administrator System admin

Information systems manager Computer trainer

Web administrator System analyst

First 2 @ ¹/₂ mark each

Name two opportunities that are available for one to further their education in ICT.

(1 mark)

College

Polytechnic University

Research institutions

First 2 @ ¹/₂ mark each

Uses 7 bits to represent character/a 7 bit character set code Codes for 128 characters

Codes for individual digits 0-9

Codes for both upper and lower case letters of the English alphabet Codes for special characters such as space

First 4 @ ¹/₂ mark each

(ii). I. State meaning of the term virtual memory as used in operating systems. (1 mark)

Simulation of primary memory on secondary memory.

1 @ 1mark

II. Describe each of the following operating systems functions:

(i) Job scheduling.

Allocation of processor/processing time to jobs/tasks

1@1mark

(1 mark)

(i) Resource allocation

Giving jobs/tasks access to resources that they need according to a priority.

1@1mark

(1 mark)

19) (a) State the meaning of the term word as used in data representation in computers. (1 mark)

Group of bits manipulated /read/written by a computer/cpu at ago/together 1@1mark

A system analyst is expected to provide a list of requirements for a proposed new computer system. Describe two requirements specification that may be included in the list. (2 marks)

Systems interactions

Input requirements

Output requirements

Processing requirements

Security requirements

Hardware requirements

Software requirements

Specific performance criterion (what system is expected to do/ ways system will be tested.

First 2 @1mark each.

Has more than one table Tables are linked

Primary key in main table links to foreign key in child table Eliminate data redundancy

Each record is unique Smaller file that flat file

First 3@1 mark each

I. State the cause of rivers of white on a publication in Desk Top Publishing. (1 mark) Fully justifying paragraph/text that caused large areas of white space between them.

1@1mark

II. Figure 3 below shows typographical dimensions of a text in Desk Top Publishing.

Label the indicated parts. (2 marks)

@1/2 mark each

(iii)

I. Differentiate between an orphan and a widow in word processing.

(2 marks)

Orphan

Paragraph opening line that appear by itself at the bottom of a page of column Widow

Paragraph ending line that appear by itself at the beginning of next page or column 1 @ 2 marks

State the meaning of the term font weight as used in word processing. (1 mark) Level of boldness or lightness of a font appearance.

1@1 mark

Study the following spreadsheet extract then answer the question that follows.

Write down the formula that would be used to determine the total votes garnered by

Candidates who ran for Deputies positions. (3 marks)

=SUMIF(A3:A8,”*Deputy*”,C3:C8)

Function name 1mark, range (sum & criteria) 1mark, criteria 1mark,

20). (a) State three ways by which information about a current computerised information system

can be gathered during systems development.

Direct observation

Interview of stakeholders

Use of questionnaires

Study/analysis of current system

First 3@1 mark each

(3 marks)

(b) The following are acronyms of computer networking protocols. Write them in full.

(i) TCP Transmission Control Protocol

(ii) FTP File Transfer Protocol

(iii) UDP User Datagram Protocol

(1 Mark)

(1 mark)

(i) A national park authority have decided to use a computer based model to develop strategies for dealing with wild fires in the park. State three advantages of using the model

to develop the strategies. (3 marks)

Many scenarios can be tried out before final strategy is determined Dangerous situations can be tried out without risks to human life

Possible fires can be predicted and strategies developed to deal with them May lead to better understanding of factors that cause the fires

May lead to better understanding of factors that encourage the spreading of the fires

Models may be revised as the nature of part plants/natural growths/forests evolve due to changing environmental conditions such as global warming.

Models can be used to train fire fighters without a need for live fire.

Frist 3 @ 1 mark each.

(ii) State three ways in which ICT could be used at home. (3 marks)

Phones could be used for communication

Spreadsheets could be used to do home budgeting Sensors could be used to detect fires

CCTV could be used to monitor security

Smart TV could be used for access to online entertainment

Word processor could be used to write letters of invitation to a child christening event

Email could be used to communicate with family members who are away from home for long periods of time

First 3 @ 1 mark

	(iii) Determine the value of 11₈-11₂+11h		(3 marks)
Conversion into one common base	1 mark
Correct working	1 mark
Correct answer	1 mark
Approaches		Approaches	Approaches
Conversion to base 2	Pure binary
Ones complement
11₈	00001001			00001001
		00001001
11₂	00000011			-00000011
		+11111100
11h	00010001			—————
		—————
				00000110
				00000101
				+00010001
				+	1
				—————-
				+00010001

00010111 _{—————-}

00010111

Approaches

twos complement

00001001

+11111100

—————

00000110 after ignoring overflow of 1

+00010001

—————-

00010111

Approaches

Conversion to base 10

11₈ 8¹+8⁰=9

11₂ 2¹+2⁰=3

11h 16¹+16⁰=17

9-3+17 =23

Ensure safety of learners/protect learners from accidental injuries

Ensure existence of an environment good for learning/ promote +ve learning environment Trains leaners on responsible use of technology

Ensure fair access to learning resources by all learners

First 2 @ 1 mark each

3. Identify four formatting that has been carried out on the spreadsheet extract in figure 1 below.

. Identify four formatting that has been carried out on the spreadsheet extract in figure 1 below.

Text Bolding,

Cell Filling/shading, cell merge

Currency

Percentage

Centering of cell content

Left alignment of cell content boundary

First 4 @ ¹/₂ mark each

Identify two ways by which the accuracy of data input into a database can be ensured.

(2 marks)

Verification Validation

2 @ 1 mark each

5. Describe two ways of authenticating users of an information system biometrically. (1 mark)

Finger print: impression or mar k made on a sur face by a per son’s fingertip, able to be used for identifying individuals from the unique pattern of whorls and lines on the fingertips.

Facial recognition: using systems that can r recognize user face by analysis patter ns on the face.

Retina recognition: using the r retina in the user eye to r recognize the user

Voice recognition: using patter ns in a user s voice to r recognize the user

Pulse recognition: using user pulse bit to r recognize the user.

First 2 @ ¹/₂ mark each

6. State two characteristics of binary numbers. (2 marks)

Made of two unique digits Made of the digits 1 and 0

Position value is determined by 2^position

First 2 @ 1 mark each

State two ways by which a national park can alert tourist currently visiting the national park about

emergency situations using Information and telecommunication technology. (2 marks)

By use of

Mobile phone sms alerts

Posting alert on websites

Use of public radio to communicate

Using social media entries to pass the alert.

8. Describe three components of the Central Processing Unit. (3 marks)

Control unit—interpret instructions and issue controls to hardware

ALU-Processes data using instructions

Memory—stores data/instructions/information during processing

Buses—mechanism for interconnection to CPU components that allow exchange of data, instructions and information.

First 3 @ 1 mark each.

State the meaning of each of the following operating systems terms:

(a)	Disk compression	(1 mark)
	Encoding of data/files so as to occupy/take less physical space on storage media
	1 @1 mark
(b)	Disk defragmentation	(1 mark)
	Locating non-contiguous fragments of file/data and rearranging	the fragments into
contiguous fragments.
	1 @ 1 mark
(c)	troubleshooting	(1 mark)
	Analyzing and solving problems in a computer system.
	1 @ 1 mark

10.State the meaning of each of the following internet terms:

(a)	Netizen	(1 mark)
	Frequent/habitual /keen user of the internet
	1@1mark
(b)	hypertext	(1 mark)
	Text attached to an hyperlink
	Text than links/connects/webpages to another/part of a web page to another.
	Any 1 @1mark
(c)	Netiquette	(1 mark)
	Correct / acceptable way of using the internet.

11.(a) Name two types of computer processing files: (1 mark)

Master

Transaction Report

Sort

Backup

Reference

First 2 @ 1 mark each

(b) State one difference between logical and physical computer files. (2 marks)

Logical file Physical file

Do not contain data Contains actual data stored

but description of records contained

in physical file

Concerned with what a file contains concern with how data in a file are contained/held

Can not exist with physical file can exist without logical file

Does not occupy memory occupies memory

View of file by the user view of file by the system

An abstraction of the file as presented abstraction of file as presented to the system

to the user.

Can be delete without deleting the physical file Can not be deleted before deleting logical file.

First 1 @ 1 mark

12. (a) List down three types of computer networks. (1¹/₂ mark)

MAN

WAN

LAN

PAN

WLAN

First 3 @ ¹/₂ Mark each

(b) List down three types of network topologies. (1¹/₂ mark)

Ring

Star

Bus

Mesh

Tree

3 @ ¹/₂ Mark each

First 3

13). Other than font weight, state four other characteristics that are used to describe a font in word

processing (4 marks)

Size of the font

Slope of the font e.g. italic

Width of the font e.g. condensed Contrast of the font

X-height of the font

Corner rounding of the font Serifs and slabs

Geometry of the font Statics and dynamics Openness of letters

First 4 @ 1 mark each

Ref: https://eugenesadko.medium.com/guide-to-10-font-characteristics-and-their-use-in-design-

b0a07cc66f7

14.(a) State two advantages of using straight changeover strategy in implementing a new computer

system. (2 marks)

Benefits of new system and realized immediately as system come to use Fast way of change system

Cheap as does not require keeping of two systems

Systems undergo better testing as there will be no room for trial and error. No need to keep data duplicates

First 2 @ 1 mark each.

(b) Describe two methods that can be used to train staff in an organization on how to use a

new computer system. (2 marks)

By use of video tutorials

By posting training material to the internet for access By use of radio

By use of social media.

First 2 @ 1 mark each

15 (a) State the meaning of each of the following information and communication technology terms:

(i) Digital divide (1 mark)

Gap between those who have access to digital technology and those who do not

Discrimination experienced by those who do not have access to digital technology

Any 1 @ 1mark

(ii) Digital citizenship (1 mark)

Digital citizenship refers to the responsible use of technology by anyone who uses computers, the Internet, and digital devices to engage with society on any level.

Ability to use digital technologies safely and responsibly

Ability to effectively use digital technologies to communicate with others

Ability to effectively use digital technologies in society/creativity/consumption of digital content

A digital citizen is a person who develops the skills and knowledge to effectively use the internet and digital technologies.

Any 1@1mark

		6
(b) State the difference between a computer engineer and a computer technician.	(2 marks)
Engineer:	plans, designs and supervise computer systems
Technician: installs and maintain computer systems (i.e. offer support to the systems)
1 @ 2 mark
Section B (60 Marks)
Answer question 16 and any other three
16. a) With the aid of pseudocode, describe two program control structures.	( 5 Marks)
Sequence	Statements are executed in series/sequence/one after the other
Start
Statement 1
Statement 2
stop
1 mark for name, 1 mark for pseudocode ¹/₂ a mark for description
Looping
Start
Repeat
Statements
Until condition is met	Segment of code/statements are/is repeated a number of times depending on a
Stop
	condition

Start

While condition is met

Statements

Endwhile

Stop

Start

For initial condition to final condition

Statements

Endfor

Stop

1 mark for name, 1 mark for pseudocode ¹/₂ a mark for description

Selection

^Start Segment of code/statements are/is executed only if a condition is met

Statement

If condition is met

Statements

Endif

Stop

1 mark for name, 1 mark for pseudocode ¹/₂ a mark for description

b). Study the following pseudocode then answer the question that follows.

START

t=0

FOR c=1 to 50

INPUT n

t=t+n

ENDFOR

OUTPUT t

STOP

i) State the purpose of the pseudocode. (3 marks)

Accept input of fifty numbers Add the numbers up

Display the total

3 @ 1 mark each.

ii) Modify the pseudocode such that it accepts any number of inputs. (2 marks)

START

t=0

INPUT max

FOR c=1 to max

INPUT n

t=t+n

ENDFOR

OUTPUT t

STOP

2 marks for initializing the using the count

^START 1 mark if only initialized but not used in count t=0

INPUT max

WHILE c<=max

INPUT n

t=t+n

ENDFOR

OUTPUT t

STOP

START

t=0

INPUT max

REPEAT

INPUT n

t=t+n

UNTIL c>=max

OUTPUT t

STOP

^{Turn over}

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