The examiner is trying to test you on the following areas;

1. Whether you are able to distinguish the CD-ROM from magnetic devices and outline disadvantages.
2. The examiner has specifically chosen the CD-ROM and not any other optical device. He/she wants you to pay total attention to the question and digout exact answers.

This question looks more direct except for the word ROM which calls for specific answers. The examiner is actually testing whether you know that the compact disk has a capacity of 700MB and these type of disks are not rewritable; actually they are called WORM-Write Once, Read Many and that magnetic media varies in capacity. From the smallest Floppy disk with a mere 1.44MB to the largest HardDisk of up to 15 Terabytes or more.
The examiner is also testing whether you know the speed of access and the speed of saving also the maintenance tasks involved of the two disks.

Yes of course. Most students are not keen in understanding questions, in this case, they haphazardly peruse through the question without taking time to digest the question requirements. Therefore, most students are likely to make the following mistakes;

1. Some may state advantages rather than disadvantages of the CD-ROM over magnetic media
2. Some may state disadvantages of Magnetic media instead of CD-ROM
3. Some may not even notice the word ROM or will just make an assumption and give answers that befit them rather than the question.
4. Some may not be keen on the number of marks provided thus give one disadvantage and move on, losing the other mark.

Two marks for the first two clearly stated disadvantages. [2 x 1 = 2 mks]

Source: KCSE Computer Studies 2012 - Paper 1
Question Number: 2 (b)
Marks: 2 marks
From Topic: Computer System, Classification of Computers
From Subtopic: Hardware, Software, Classification of Computers according to size
Question Level: Form 1

The examiner would like to know the following:-

1. Whether you understand these terms
   1. Hardware
   2. Software
   3. Portability
2. Whether you are able to differentiate between hardware portability from Software portability

1. Differentiate is the major keyword in this question. The examiner could want to establish whether you can differentiate between hardware and software portability
2. Another major development in this question is the word portability. The way the word may be used with hardware, cannot not be the same way it may be used with software. The examiner wants to dupe you into a box of confusion. Watch out!

1. Defining rather than differentiating. Well, if you can define, clearly show the distinction between hardware portability and software portability.
2. Students define or distinguish between hardware and software without inclusive of the word portability, thus, blowing the question out of context.

• Hardware portability refers to the ease of moving hardware from one location to another. while
• Software portability refers to the ability of running software on different platforms/models/hardware/computers

Two marks were awarded thus one in each clear definitive distinction

Source: KCSE Computer Studies 2012 - Paper 1
Question Number: 1
Marks: 2 marks
From Topic: Computer System
From Subtopic: Central Processing Unit (CPU)
Question Level: Form 1

The examiner is testing on the following areas

1. Whether you understand what a control unit is, and if you do;
2. What is the role of a control unit

The examiner has phrased the equation "state two functions of the control unit of a computer"

1. The examiner has used the word 'state'. State here means to formally write or say something, especially in a careful and clear way according to Dictionary.com. State here simply means to list by explaining especially in short sentences.
2. Another keyword used in this question is 'two functions'. Well, it should be known to you that the functions needed are only two, this calls for listing. Thus, you can state the answer by listing two functions of the control unit of a computer. Watch out! these two functions have a clear relationship with the number of marks provided.
3. Lastly but not least 'the control unit of a computer' the examiner is hiding something here. He actually does not want give you a hint. That is why he/she has used the word 'computer' instead of 'CPU'​ most students who never did extensive preparations will find this question to be tricky and confusing

1. For those who don't understand what the control unit of the CPU is, they give irrelevant answers or answers which are out of context, alternatively most students who have no idea, leave the space blank without giving the answer and end up scoring zero.
2. Instead of giving functions, students define what a control unit is. This is a weakness of not reading the question carefully and taking each phrase into consideration. They end up scoring blanks.
3. Candidates state more than two answers of which the first or second answer is wrong thus losing some marks. Here is an example:
   1. Correct answer
   2. Wrong answer
   3. Correct answer -      [in these kind of answering, only the first two choices count. the third and forth may be correct but don't tally the final mark either they don't add value to the question. Candidates are therefore advised to give the first two correct answers and if they wish to add extra answers of which they are not sure of, they should occupy last slots]
4. Candidates state only one choice and end up losing the other mark.
5. Candidates list answers without further explanations to backup the answers. Candidates are therefore advised to clearly explain their answers.

1. To direct the operations of the internal processor components.
2. To control the flow of programs and data in and out of main memory.
3. To read and interpret program instructions.
4. To control flow of information to and from all the components of the computer.
5. To control flow of information/data
6. To determine next instruction to be executed first.
7. To fetch instructions from devices.
8. To direct/give/monitor operations of internal processing.
9. To send control signals to peripherals.

Any 2 x 1 = 2 Marks. This means one mark is awarded to any answer stated. For two answers, the candidate scores two marks