Saturday, March 23, 2013

Information processing

Information processing

1 The diagram shows a general data processing cycle. What should be written in the two empty boxes?

Information processing 

 

The date 24th May 1988 is stored as 240588 on a computer data file.

(a) Give two reasons why a date should be coded rather than stored in full.

(b) When the date is entered it is both verified and validated. Explain the terms verification and validation.

 

A school uses a computer to store information on its pupils. One of the files holds information in coded form regarding the examination results of the pupils. Some of the fields used are as follows:

Subject      Level      Mark obtained         Date of examination

The codes used for each field are:

Subject 001 = English

              102 = Maths

              304 = Physics

Level    02 = GCSE

              03 = A Level

              04 = Oral

The 'mark' is a 3 digit number in the range 000 to 100.

'Date of examination' is written in the following way:

1087 = October 1987

0686 = June 1986

(a)interpret the following codes :

(i) 102020560585

(ii) 001040831187

(b) Encode the following: a mark of65 in an 'A' level Physics examination taken in Junc 1984.

(c) Errors can be made on entering information. Give one example of an incorrect entry to:

(i) the date field.

(ii) the mark field.

(d) Suggest one extra field that might be useful and give a reason for your choice.

 

Ring two of these items which are methods of data collection for input to a computer system.

survey forms bar codes printers televisions ROM

 

Description: The action involved in collecting data for a particular computer process, such as the continuous collection of temperatures in a chemical process.

Term: ………………………………………………………………………………………

 

The Beechill Youth Club decides to use a computer to keep records of its members and their interests. The club needs to collect certain data about each applicant. The information will be stored using a file handling package. The file will contain the following data fields:

Surname, first namets), street address, post code, tel. number, date of birth, interest 1, interest 2.

When a young person applies to join he/she is asked to complete this application form. Place the field names opposite the boxes where you think the fields should be.

Information processing2

 

An electricity board uses a computer-based system to charge customers for the electricity they use. Each customer has a meter which records the amount of electricity used (see diagram below). Every three months a meter reader visits the customer's house to read their meter. The new meter reading is written on a data collection form next to the customer's account number. Using the new meter reading and the previous meter reading the actual electricity used can be calculated. The customer is then sent the bill for the electricity used.

Information processing3

A typical electricity meter

This would be recorded on the data collection form as

5

7

8

2

1

(a) Design a suitable data collection form to allow the meter reader to visit each customer and record the new meter reading. Show clearly which information is printed by the computer and which is written by the meter reader.

(b) The electricity board keeps a record of each customer's details. Describe the different fields you would expect to find in each customer's record that enable the system described above to function.

(c) A customer receives an incorrect bill for about £1,000,000.

(i) Explain how this could happen.

(ii) What steps could be taken to prevent this?

(d) Customers often telephone the electricity board to enquire about bills, etc. The telephone operator must be able to access each customer's details immediately in order to answer their enquiries. Describe a suitable computer-based system to achieve this. Make specific reference to the required hardware, operating system features and method of access to the data files.