Knowt
Chapter 7
A book has an ISBN which is 330247204X Tick (✓) the most appropriate data type for the ISBN.
A Numeric: integer
B Text
C Boolean
D Date
A systems analyst has been asked to carry out an analysis of a company’s current computer system.
(a) State three methods of analysing the current system.
1 Observation
2 Interviews
3 Questionnaires
—> Examination of existing documents
(b) The systems analyst is working with a team to create some new software. The software documentation will be stored on the cloud. Describe how the team can use the cloud to share the documentation.
Documentation is uploaded to the cloud
Access is given to members of the team
Members of the team log into the cloud
Members of the team open the documentation
Members of the team update the documentation
Documentation is synced
Can be tracked by the owner of the document
Several copies of the document are made
Identify the most appropriate method for reducing data entry errors from the descriptions given.
(a) Manually checking the data without reference to the original copy
Proofreading
(b) Checking that the data being entered is reasonable.
Validation
(c) Preventing errors when data is copied from one medium to another
Verification
A book contains a bar code whose number is 503619309903 Tick (✓) the most appropriate validation check to test the validity of the bar code.
A check digit
B format check
C range check
D spell check
A student is creating a spreadsheet that includes a formula to check a number entered in a cell is between two values
The number is entered in cell A10 as an integer.
If the number is between the two values then a message ‘OK’ is displayed, otherwise ‘error’ is displayed.
The formula the student has created is:
=IF(AND(A10>1,A10<32),"OK","error")
Data will be used to test the formula.
(a) Identify two items of extreme test data the student should use and give the reason why this data was chosen.
Extreme test data 1: 2
Extreme test data 2: 31
Reason: To test the boundaries (of the formula)
To test the comparisons are correct
(b) The student has entered an item of abnormal test data. Explain why abnormal test data is used.
To test that data outside the range is not acceptable
To test that the correct data type is entered
To test that the error message works
To test that the errors are trapped correctly
A book has an ISBN which is 0 330 24720 Tick (✓) the most appropriate validation check to test the validity of the ISBN.
A character check
B format check
C length check
D range check
A teacher is creating a spreadsheet as an electronic mark book. Part of the electronic mark book displays how well a student did on a piece of work. When a student completes a piece of work the teacher will enter the mark into the electronic mark book and a message will be displayed.
• If the student gains 60 or more marks then ‘Merit’ is displayed
• If the student gains 50 to 59 marks then ‘Pass’ is displayed
• If the student gains a mark below 50 marks then ‘Not Pass’ is displayed.
The formula the teacher has used is: =IF(A1>=60,"Merit",IF(A1>50,"Pass","Not Pass")) The formula will need to be tested. The teacher will do this by entering test data into cell A1.
(a) Explain the steps that need to be taken to test the formula. Include in your answer any test data used and the reasons why these were chosen.
Enter test data
Run the formula
If actual output does not match expected value make corrections to formula
Re-test the formula
(b)When the teacher enters a mark of 50 he expects ‘Pass’ to be displayed. State the changes he needs to make to the formula to ensure ‘Pass’ is displayed.
Change A1 > 50 to A1 > = 50
Change A1 > 50 to A1 > 49
(c) When the electronic mark book is complete it needs to be tested with live data. Explain what is meant by live data
Real data relating to tests that have been carried out previously
To ensure that the electronic mark book should work with real data
State three items that should be included in the technical documentation of a computer system
Purpose of the system/program/software
Limitations of the system
Program listing/coding
—>Program language used, Program flowcharts/algorithms, System flowchart, Hardware requirements, Software requirements, File structures, List of variables, Input format, Output format, Sample runs/test runs, Validation routines/rules
Tawara Stores is a small company that does not make much profit. The managing director is deciding whether to implement a new IT system using direct changeover or parallel running.
Describe the advantages and disadvantages of using direct changeover compared with parallel running in this scenario.
Advantages
Benefits are immediate whereas with parallel running it takes time for the new system to be fully running
With direct they only have to pay for one set of staff therefore saves costs
Costs are saved as only one computer system is needed
With direct the maintenance is cheaper as there is only one set of computers
Data is only entered once so saves duplication of data
The new system is checked thoroughly before implementation
Disadvantages
Staff have to be trained and be fully ready to use the new system before it is implemented
Staff cannot be trained on the new system whereas in parallel both systems are running
If there is a problem, then all the data can be lost; this could be disastrous for the company whereas in parallel there is the original system
With direct staff cannot be trained gradually
Verification and validation are used to check data.
(a) Identify and describe two methods of verification.
Visual verification
Re-reading the document referring to the original
Double data entry
One person types in the data again referring to the original document
A second person types in the data from the original document and the two entries are compared
(b) Explain the following validation checks.
(i) Presence check
Checks that the data has been entered/present into the field
(ii) Type check
Checks the input data does not contain invalid characters
Checks the data contains the correct data type
A developer is writing a program to record the results of examinations taken by students in a school. The program will be tested to make sure that it works. There are three types of test data that can be used to test a system: normal, abnormal and extreme.
Explain what is meant by normal, abnormal and extreme test data.
Normal
Data is within the range of acceptability
Abnormal
Data outside the range of acceptability
Data that is of an incorrect type
Extreme
Data that is on the boundary/limit of acceptability
A technician is setting up the hardware for the video-conference. State three tasks the technician would need to do to set up the hardware for the videoconference. You can assume that the hardware required has already been purchased.
Ensure the video camera/webcam, microphone, speakers/headphones are switched on
Ensure the hardware devices are connected
Carry out tests on the microphone, video camera/webcam and speakers/headphones
—>Adjust the video camera/webcam so the headteacher can be seen, Check the volume levels, Check internet connectivity
A media student is creating a movie, in school, for a project. He needs to take the movie home to edit it. The student intends to use a CFast solid-state memory card to transport the movie files. The student is unable to save the work on the memory card.
Give two error messages that may appear when attempting to save the work.
Medium is full
Corrupt card
—>Write error, Card error, Card not initialised, Virus found on the card, Device not recognised
A teacher is setting up a database which she will use to record her student’s exam marks.
(a)The teacher is planning to test the mark range using different types of test data. The range of marks that the teacher can award is 0 to 100.
(i) Write down one example of extreme test data that the teacher can use to check the range.
0
100
(ii) Extreme test data is one type of test data. The teacher uses two other pieces of test data. Write down the type of test data for each of the examples.
TEN Abnormal
55 Normal
The secretary of a sports club is setting up a database of members to replace the current manual system. He will need to create a database structure.
(a) Describe the steps involved in setting up and testing the database structure before it can be used in the new system.
Steps that could be done:
Load the database software
Set up tables
Set up field names
Set up primary/foreign key fields
Set up relationships
Set up the field types/properties/formatting/data types
Set up the validation routines
Set up input forms
Set up queries/reports
Type in/import records
Create a test strategy/plan
Data and testing:
Test using normal, abnormal, and extreme data
If errors are found, make corrections
Re-test the database structure
Test with live data
To get full marks need at least three points from each
(b) Describe the term parallel running, giving the benefits and drawbacks of using this method of implementation.
The old and new systems/both run side by side until the new system takes over
Benefits
The old system can be used as a back up
Staff can be trained gradually
Drawbacks
More time consuming as the data needs to be entered into two systems
More chance of error on data entry as two systems are being used
More costly as there are two sets of staff
Uses more power running two systems
Proofreading is often confused with visual verification. Describe the differences between proofreading and visual verification.
Visual verification refers to the original document whereas proofreading does not need to refer to the original document
Proofreading is checking spelling and grammar errors whereas visual verification does not check for errors
Visual verification checks that the data has been copied correctly
The restaurant owner is planning to upgrade the software used to book reservations. He has employed a systems analyst who is analysing the current system. The systems analyst can either send out questionnaires for staff to answer or observe staff working with the current system.
Discuss the advantages and disadvantages of using questionnaires that staff answer rather than observing staff to gather information about the current system.
Advantages
Answers are more honest as they are anonymous
Staff can remain anonymous whereas the observation cannot be anonymous
Can be sent to all the staff at the same time whereas the observer may only see one part of the operation
Questionnaires can be filled in at any time whereas observations can only be carried out when the restaurant is working
Analysis of questionnaire can be carried out automatically whereas
observations the observer must produce notes
Observer may miss elements whereas questionnaires are filled in by the users
Disadvantages
Users do not always complete the questionnaire and hand it back but observation watches users working
Work rate can be influenced by being observed but this does not apply to questionnaires
More chances of incorrect data if question not understood
The observer can see exactly how the system works well and not so well whereas a questionnaire takes the users viewpoint
A school librarian is setting up a database of all the revision books he has in stock. The school library sells revision books to students. The books range in value from $1 to $10 and are available either in electronic book type (E) or physical book type (P).
(a) The librarian is planning to set up a number of different types of validation rule for the fields to check data entry. Write down the most appropriate field name from the table that could be used with each of the validation rules. Your answers must be different in each case.
Presence ISBN
Lookup Book_type
Range Cost
Length Department
(b) The librarian needs to set up a primary key field. Write down the most appropriate field name from the table that could be used as a primary key field.
ISBN
(c) Most of the revision books are available in electronic book type as digital versions of the printed books. These are stored as interactive PDF files.
Describe the benefits and drawbacks of using the digital versions.
Benefits
Digital therefore can easily be used in other documents/software
Instant access on many devices
More accessible for disabled
Quicker to search digital books
Drawbacks
Health issues with using a computer to read the book
Cannot be written in braille
May require extra software/reader
Never own the book as it is only data
Need to purchase a device to read them
Needs the internet to download the book
Tick (✓) whether the following statements refer to control, measurement or modelling systems. Only tick (✓) one answer for each statement.
Tawara School is presenting a concert. For previous concerts the booking of tickets was carried out manually using pen and paper. For this concert they are going to use an online booking system.
Identify the most appropriate method of implementation of the new online booking system in this scenario.
Direct changeover
Explain, giving reasons, why your answer is the most appropriate method of implementation for this scenario.
Benefits are immediate
Cheaper as there is only one set of staff
Less chance of the new system being faulty as it is thoroughly tested
Only one system in operation therefore data is not duplicated
For each of the fields shown, name and describe one validation check that could be used on the data. Your answers must be different in each case.
(i) Vehicle_licence_plate
Presence check
To make sure that it has been entered as its unique
OR
Format check
To fit in with the layout
(ii) Cost_of_service
Type check
Digits only
OR
Range check
Between 1500 and 5000
(iii) Date_of_service
Format check
To ensure it is dd/mm/yyyy
OR
Range check
To ensure it is between certain dates
OR
Length check
Maximum of for example 10 characters
The owner of a soccer club has employed a systems analyst to create a new computerised system to store details of club members. The systems analyst starts by researching the existing system. One way he could do this is to interview members of the soccer club.
(a) Discuss the benefits and drawbacks of individually interviewing the members.
Benefits
Gives the opportunity for the member to give more honest answers
The questions can be expanded/modified/added to following previous questions/answers
Allows more detailed answers to be given rather than questionnaires
Questions can be explained
Can see the body language
Drawbacks
Takes a long time to interview all the members using this method
Both the members and the interviewer have to be free at the same time
This method is expensive as the system’s analysts time is expensive
The member cannot remain anonymous, so they cannot express themselves properly
The member feels that they give comments that the interviewer wants to hear
(b) When the systems analyst created the new system, he had to choose data types for each field. Write down the most appropriate data type for each field. The answers in the table must be different in each case. The data type for one field has already been identified; this data type must not be used for the other fields. For any numeric field specify the type of number.
Year_joined Numeric: Integer 2019
Gender Boolean/logical F
Date_of_birth Date 04/11/2000
Membership_number Text 01254
Cost_of_membership Numeric: Currency$10.50
(c) The systems analyst has set the data type for the Membership_number field as text. Explain why this field has been set for a text data type rather than a numeric data type.
The field would not be used for calculations
There is a leading zero in the data
Text fields take up less space than numeric fields
A teacher has set up a database for a class library. The data about the books in the class library will be entered by the teacher. The data can be verified by double data entry or visual verification.
(a) Compare double data entry with visual verification. Your answer must include similarities and differences.
Similarities
Both are used to check that data has been entered correctly
Both ensure that the data has been transferred correctly
Both are used to check the data against the original data
Differences
In visual verification the user compares the data
Data is compared with the original data source
In double data entry the computer compares the data
In double data entry the data is compared with the previously entered data
In double data entry data is entered twice by the user(s)
When data is entered into a date field it is validated. An example of the data that could be entered is 01/04/2023 State two validation checks that could be used on this data.
Format (check)
Length (check)
Range (check)
Type/character (check)
A teacher is creating a database for a class library. The teacher types the details of each book into the database. The teacher has entered a number of records
Identify and describe a validation check based on the data shown in the database table, which could be applied to the data as it is entered into each of the fields. Give a validation check and its description. Each validation check must be different.
Book_number
Length check
Each data item must be exactly 4 characters long
Character check
Each data item must be an integer
Range check
Data must be in the range 1000 to 9999/1999
Presence check
To check that the field has data//not null
Date_acquired
Format check
First two numbers followed by a slash then next two numbers followed by a slash then four numbers//DD/MM/YYYY
Range check
Checks the date is between two dates
ISBN
Check digit
The number is checked by calculation of all the separate numbers
Character check
Data must be an integer
A hospital administrator enters data from medical forms into a database. Validation and verification are both used when entering data to minimise errors.
Explain what is meant by validation and verification and why they are both needed in this scenario
Validation
Validation is an automatic computer check
Validation ensures that the data entered is sensible/reasonable
Ensures the data entered fits the set criteria
Verification
Verification checks that the data on the original source document is identical to the data that you have entered into the system
Verification ensures that the data is copied/entered correctly
Why they are both needed in this scenario:
Because it is personal data the data needs to be correct
Data should be error free to ensure patients are safe
If data is incorrect it could lead to consequences
Individually they cannot detect all errors
The manager of the Tawara Hotel has decided to computerise the hotel’s room booking system. The new booking system will allow customers to book rooms online using an app on their smartphones. The manager has employed a systems analyst who will carry out research into the current system by examining existing documentation and completed questionnaires from staff. One item of information that the systems analyst will need to identify is problems with the current system.
(a) State three other items of information that the systems analyst will need to identify:
The inputs/processing/outputs of the current system
The user requirements for the new system
The information requirements for the new system
Hardware/software requirements
(b) Following the analysis, the systems analyst will implement the new system using either parallel running or direct changeover. Evaluate these different methods of implementation.
Parallel running
Data would need to be entered twice this could cause issues with double booking
Staff can be gradually trained on the new system which takes a longer time
Parallel running is more expensive to operate as there are two sets of staff/two systems operating
In parallel if the new system fails, the old system is still available
In parallel running a system is always in place
Direct changeover
Faster method of full implementation as the hotel will not want the system to be out of use
Immediate benefits
System is thoroughly tested before use, therefore less chance of it being faulty
Staff have to be trained before the new system is implemented this can be difficult as they are still working
Training takes place on non-live systems which may mean problems can be missed
Data can be lost as the old system has been removed
No system will be in place during the changeover
To gain full marks there needs to be both direct changeover and parallel running
Peter needs to create a validation check for product numbers. Three examples of product numbers
he needs to check are:
977135120127916
976143148163921
845132120651166
Identify two validation checks he could use to check the numbers.
Check digit
Range check
Character/type check
Length check
Type check
A school has employed a systems analyst to help update its computerised examination system. The systems analyst researches the current system to see what will be required in the new system.
State the methods of researching the current system that are described:
(i) talking to the network manager and examinations officer about the current system
Interview
(ii) watching the users operating the current system
Observation
(iii) forms sent out to all users to complete and return
Questionnaires
After completing the analysis, the new system needs to be designed. One item that needs to be designed is a file structure. Identify the other items that would need to be designed.
Data structure
Input format
Output format
Validation routine
Tick (✓) the most appropriate method of implementation to match the statements below
A system can be analysed using different methods. Discuss the advantages and disadvantages of analysing a system by interviewing staff rather than using questionnaires
Advantages
Questions can be explained if they are misunderstood this cannot happen with questionnaires
Questions can be asked relating to the answers given previously
More detailed answers can be given
More complex questions can be asked
Questions can be changed to suit the person being interviewed
The person being interviewed tends to answer all the questions
Can see body language
Disadvantages
They are not anonymous whereas questionnaires are
Takes far longer to complete than a questionnaire
The interviewer and interviewee must be available at the same time
More expensive as the interviewer has to be hired and interviewee needs time off
Answers may not be honest//more honest with a questionnaire as the person is anonymous
Answers may be skewed by the interviewer
Answers in a questionnaire can be analysed quicker through OMR
Questionnaires tend to be sent to more people
To gain full marks the discussion must have correct answers for both interviews and questionnaires
The manager of a medical centre keeps the doctor’s stock records in a database. The stock for any item is not allowed to fall below 15 items and the manager keeps a maximum of 100 items in stock. The table shows examples of the stock.
As data is entered it needs to be verified and validated.
(a) Explain why verification is carried out.
Checks the data entered/transferred/copied correctly
Matches the original document
(b) Write down the field name from the table that would be the most appropriate for each of these validation checks. Each answer must be different.
Check digit: Serial_number
Length: Shelf_number
Type: Number_in_stock//Name_of_supplier//Name_of_item
(c) Name the most appropriate field from the table that could be used as a primary key in the database.
Serial_number
The owner of Tawara Hotels is planning a new computerised booking system. There are ten Tawara Hotels throughout the world. The current booking system allows people to book rooms in any of the Tawara Hotels. He has employed a systems analyst to research the current system and then install the new system. When analysing the current booking system, the systems analyst must identify the user requirements.
Explain why it is important for the systems analyst to do this
The systems analyst is creating a system that is just for the client
Important to meet the needs of the user; so it is customised
Reduces the costs if the new system matches the existing hardware and software
More efficient system is produced that does what the users require
(b) Tick (✓) the relevant stage of the systems life cycle for each of the following activities.
Before the new booking system is installed, the systems analyst has to decide on a method of implementation. One method of implementation is pilot running. Name other methods of implementation and describe two benefits of each.
Direct changeover – 1 mark
Benefits are immediate
Costs less as fewer staff are needed
Costs less as only one system is required
Less likelihood of malfunction as system is fully tested
Parallel running – 1 mark
If new system fails, old system can be used as a back up
Possible to gradually train staff
Phased changeover – 1 mark
If the new system fails, only one part is affected
Easier to ensure that part of the system is fully operational before moving
onto the next part
Possible to train staff in one part of the system, therefore less costly than parallel
Possible to gradually train staff
Tick (✓) whether the following descriptions of analysing a system refer to Interviews, Observation or Questionnaires
A hospital is creating a database to store blood donors’ medical details. The fields in the database include Health_number, Date_of_birth, Gender and Blood_group.
(a) When a new blood donor wishes to give blood they need to fill in a form. Each blood donor has a unique health number which uses a 10-digit number, for example 9434765919. Blood group can be A, B, AB or O. Part of the form is shown below.
Question 1 Numeric: integer / text
Question 2 Date/time
Question 3 Boolean/logical
Question 4 Text/alphanumeric
In the Blood_group field the only data that can be entered is A, B, AB or O. Tick (✓) whether each of the following blood groups is an example of abnormal or normal data.
(c ) The administrator needs a list of all the blood donors in the database with blood group A as well as in the same list all the blood donors with blood group AB. This list will only include female blood donors.
To find the blood donor with the health number 9434765919 he will need to type in the following query. Health_number = 9434765919
Write a query to find all the female blood group donors with the blood group A as well as those with AB.
Gender = F AND Blood_group = A*
(d) When the details of a new donor are added to the database the person’s date of birth is entered. Explain why the administrator would prefer their date of birth to be stored rather than their age.
The age changes every year therefore it will need to be changed regularly —>administration of the database becomes more time consuming.
The age of the donor can be easily and automatically calculated from their
date of birth —> improving accuracy.
Data only needs to be entered once —> reducing errors.
(e) Name the most appropriate validation check for the Health_number.
Length check // Range check
