State two functions of the control unit of a computer

Analysis of the question

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

What does the examiner want?

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

Examiner tricks

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

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Mistakes that students make

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.

KNEC Marking Scheme & 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.

How Marks are awarded

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