CP1 Computing June 2004

The documentation of a computer system is very important.

State two distinct types of documentation, indicating in each case the type of person who would use this documentation.

[2]

user documentation - used by the user of the computer
technical documentation - used by a programmer or technician

2(a)

A certain programming language is very good at handling complex calculations.
Name an application which could sensibly be written in this type of programming language.

[1]

a scientific application - eg an engineering CAD package

(b)

Three features of another programming language allow:

access by different browsers
different fonts to be displayed
different layouts to be displayed

(i)

What is the main purpose of this type of programming language?

[1]

to create Internet web pages

(ii)

Describe two other features which make this type of language suitable for this purpose.

[2]

hyperlinks - to move from one page to another
graphics can be embedded in the page

3 (a)

Describe one situation where a binary search is more appropriate than a linear search.

[1]

when the data is sorted into order of a keyfield

(b)

Describe one situation where a linear search is more appropriate than a binary search.

[1]

for a serial file where the data is jumbled and in no particular order

4(a)

Standard modules are often used in programs. Give two reasons why standard modules are useful.

[2]

it saves time as subroutines do not have to be written again
fewer errors as the subroutines have been tested and debugged already

(b)

Describe what is meant by the term self-documentation, giving one example.

[2]

a program listing which contains explanations about itself
Eg - there may be a number of comments included in the listing

A software company is developing a program for a small manufacturer to provide stock control and sales information for its staff. This program will replace an existing system now felt to be inadequate.

(i)

During the systems analysis stage of this development, a requirements analysis is carried out, and a requirements specification is produced.

(I)

Describe two activities which would happen during the requirements analysis.

[2]

interviewing the staff and management
asking staff to complete and return questionnaires

(II)

describe two items which would be included in the requirements specification.

[2]

aims and objectives of the new system - what the system must be able to do.
evaluation criteria - how to judge whether the system is working well

(ii)

It is important that the software company carefully considers the human computer interface (HCI) of the new program. Give two reasons why this is important.

[2]

the HCI must be appropriate to the IT skills of the users - or they will be unable to use the system.
if not designed properly it may not be possible to use some parts of the system

(iii)

During the life-time of the program, various types of maintenance will be required.

(I)

While the program is being used, an error is discovered. What type of maintenance is required in this case?

[1]

corrective maintenance

(II)

It is found necessary to make some changes to the program so that it will run on a different operating system. What type of maintenance is required in this case?

[1]

adaptive maintenance

(III)

Name a third type of maintenance and describe a situation where this type of maintenance will be required.

[2]

perfective maintenance
eg. an improvement may need to be made to speed up processing

A number of measurements are taken during a chemistry experiment and various types of data are recorded for entry into a computer program.

The data includes:

the measurement number (for instance 1, 2, 3...)
the name of a chemical (for instance sodium chloride)
the temperature (for instance 54.6)
whether or not a solid is formed (TRUE or FALSE)

(i)

State the most appropriate data type for each of the following:

[4]

(I)

measurement number;

integer

(II)

chemical name;

string (text)

(III)

temperature;

real

(IV)

whether or not a solid is formed;

boolean

(ii)

A rogue value is used as one of the data measurement number. Give an example of a suitable rogue value in this case and state its purpose.

[2]

-1
to let the computer know that there is no more data to be input

(iii)

A record could be used to store all four items for one measurement. Why would a record be suitable in this case?

[1]

because there are a number of different data types

The following program extract (which contains two errors) is intended to calculate the total profit on a number of items sold. The selling price and cost price are input for each item and the profit for that item is the difference between the two.

TotalProfit = 0
for Count = 1 to NumberOfItems
     ipnut SellingPrice, CostPrice
     Profit = SellingPrice + CostPrice
     TotalProfit = TotalProfit + Profit
next Count

(i)

This extract contains two types of program error. In each case,

name the type of error
write down the corrected line

[4]

syntax error (ipnut)
input SellingPrice, CostPrice
logical error
Profit = SellingPrice - CostPrice

(ii)

Name one other type of program error and state a situation where it will arise.

[2]

execution error
For example if trying to divide by zero

A number of people own holiday properties which they wish to rent out. Country Escapes is a company which keeps a database of such properties.

When an owner wishes their property to be included in the database, they contact Country Escapes who visit the property to check its standard before adding its details to the database. If the property is accepted, the situation described is shown in the diagram below:

(i)

What is the name of this type of diagram?

[1]

data flow diagram

(ii)

What type of object does the shadow box in the diagram represent?

[1]

external entity

(iii)

Give a suitable name for the object shown as a in the diagram.

[1]

property owner

(iv)

Give a suitable name for the object shown as b in the diagram.

[1]

property details

(v)

Give a suitable name for the object shown as c in the diagram.

[1]

database of properties

(vi)

Draw the shape used in the diagram to represent a process.

[1]

(box with rounded corners)

(vii)

Draw the shape used in the diagram to represent a data store.

[1]

(open ended box)

Doctors in a general practice wish to vaccinate high-risk patients against a particular infection.

There are three types of patients considered to be high-risk.

very elderly people
less elderly people who consulted the doctor frequently in the previous year
young children

The algorithm used is shown below:

Statement
1	input Age
2	input ConsultationsLastYear
3	if ((Age>75) OR ((Age>65) AND (ConsultationsLastYear>5)) OR (Age<5))
4	then output "Vaccinate"
5	else output "Don't vaccinate"

(i)

State what the output will be for:

  (I)     a patient aged 4 with 4 consultations the previous year;
(II)     a patient aged 4 with 7 consultations the previous year;
(III)     a patient aged 82 with 8 consultations the previous year;
(IV)     a patient aged 70 with 2 consultations the previous year.

[4]

Vaccinate
Vaccinate
Vaccinate
Don't vaccinate

(ii)

The algorithm is changed so that statement 3 now reads:

3	if ((Age>75) OR (Age<5))

(I)

Give an example of input data which will now give a different result from the original algorithm.

[1]

a patient who is aged 66 and had 8 consultations (previously would have been vaccinated but now would not be)

(II)

Suggest why this change might have been made.

[1]

it decreases the number of people to be vaccinated - so it would take less time.

10.

In the following question, additional credit (up to 3 marks) will be gained if your answer demonstrates skill in written communication.

Office staff in a school use a computer package of linked programs which provide word processing, spreadsheet and database capabilities. Facilities available include editing, mail-merge, macros and sorting.

Describe in detail the facilities shown in green which are available in a package of this type.

[9+3]

Editing facilities would be provided in all the programs which would allow the staff to add new data, change existing data or delete unwanted data.

Mail-merge would allow the staff to create a number of similar documents. This would be done by creating a standard form letter which included fields stored in a separate database. When the documents are printed the data is input from the database and inserted into the correct place in each document.

Macros are single instructions which, when run execute a pre-defined sequence of instructions. They will save the staff time when performing repetitive tasks. Macros may be defined in all of the programs used by the staff.

Selected data may be sorted into alphabetic or numeric order of a key field in a database or on a spreadsheet. Options may be available for sorting in ascending or descending order.