Give two reasons why a client would be involved in the testing
- Software can be tested on their own systems
- Software can be tested on eventual users
- Client can provide feedback to software development company
Why is an emulator required when writing a program on a PC that is intended to run on a mobile phone?
To run the object code/exe/machine code for a different processor than the one in the computer
What additional backups would be required to ensure no loss of data in the event of a system failure on a system which uses daily backups?
An incremental backup would ensure no loss of transaction data in between daily backups
Explain why RAD could be beneficial to a company who are bidding for a contract to develop software for a multinational supermarket chain
RAD involves the creation of prototypes/models working software
Prototypes can stimulate user interest in the software as they can use a working copy with limited features
How could agile methodologies be used in the effective production of the software?
Regular opportunities to assess development/success
Shorter iterations of work/quicker response to change
Gather requirements at the same time as developing software
Greater customer collaboration/cooperation
How can 32 bits be used to store real, negative values?
Allocate 16 bits for the mantissa and 16 for the exponent
Two’s complement for the mantissa would allow negative values
Twos complement for the exponent would allow for smaller values
Why are compilers often more efficient than interpreters?
A compiler saves the object code and so does not retranslate on each pass through the loop
It would not stop at every line one by one which is a slow process
An interpreter may retranslate on each pass through the loop using processor time
An interpreter is resident in memory where as a compiler does not need to be in memory
Explain the benefits of code being kept in cache memory
The processor could fetch data in the query and save time (faster execution)
Faster access time than main memory
Describe two advantages of using a 1-D array in order to store a list of values instead of individual variables
Only one line of code renamed to create multiple values
Passing parameters is easily implemented with one line
Each individual element in the array can be resembled by indexing
Explain the purpose of a trace table
Used to test algorithms for logic errors by tracking the processes that occur throughout execution
Explain why it is common for a loop to fail to terminate during program execution
If counter is reset to 1 on each iteration of a loop
This causes the terminating condition of the loop to never be met
How could an algorithm be corrected should a loop fail to terminate?
Setting the counter to position + 1
Describe an error which can occur during program execution other than an execution error
A logic error is when the code fails to produce a correct output because of the result of an incorrect formula or using incorrect/wrong algorithms
A syntax error occurs when the programmer enters a word which is incorrect for that environment and so stops the program from translating/executing eg if words are misspelt/used incorrectly
Describe how a feature of a software development environment could have been used to locate the area of code which contains an error
Breakpoints
Allows execution of code to be stopped at a pre-defined point
What two factors could be considered whilst using wire-framing?
Navigational Structure - Relationship between links and take into account the nature of navigation
Presentation of data - Placement of objects in order to maximise purpose of the page for end user
Describe how a subroutine can make a value available to other parts of a program
By declaring it as a parameter which can pass a value to a corresponding parameter
Give reasons why a dynamic database-driven website is a benefit for site users
- A dynamic website will respond to information entered by the user
- Information will be recent/up to date
- Visitors will be presented with information that relates specifically to their needs
Give an example of a type of input validation which can be applied to a username when it is first registered
- Validated against the list of existing usernames
- When registering the system must make sure that the username does not exist in the database already
- To check that no invalid characters are included
Describe the main features of a contemporary development in intelligent systems
Game playing program that can learn and develop strategies
Describe two ways of improving form usability
Changing the data type of certain fields
Offering buttons for Boolean options
Create drop down menus for certain fields as a method of restricted choice
How could a company use database software to produce a report?
Create a query with the required fields
And then create a report using data from the query
Describe ways a company can ensure that a website is optimised for indexing by crawler software
- Ensure that the title tag contains a concise description of the web sites content
- Create a new title tag for each web page
- Use the description meta tag to add more detail about the page
- Use URLs that are as concise as possible
Explain how HTML code can be altered to make web pages accessible should images fail to appear on screen
Through use of appropriate ALT tags to include a better description of each image
Explain why the use of lossless compression would result in a significant reduction in file size for an image of a national flag
It has long runs of pixels the same colour which allows the colour and the repetitions to be stored using just two values
Give reasons as to why server-side validation may be more appropriate than client-side validation when dealing with or so that keep track of progress
- Updating constantly held data/data services is not possible with client side scripting
- Validation cannot be disabled if it is handled on the server
- Less security issues if data is managed at the server
Explain why cloud storage might be best suited for storing updates on a shared web-based folder
- It allows multiple users to share, edit and save files/folders
- Accessible via the Internet from any device and/or location
Describe the financial implications of RIPA for Internet service providers
- ISPs must implement technical systems for the storing and interception of information which may be requested by the government
Why is RIPA becoming increasingly difficult to enforce?
Encryption us becoming more sophisticated/difficult to decrypt and so this requires the cooperation of individuals to provide keys/information in order to decrypt/access data
How can accessible design be achieved through the use of cascading style sheets?
- CSS media queries are used to identify the target device/system
- CSS rules are created for different screen widths and devices
How can code be altered to optimise load times?
- Through creation of a CSS file to hold the CSS rules so that less data is delivered with the main page
- Merge any JavaScript files into one and include file to reduce fetches from the server
- Merge any images into one image and use CSS rules to display only the relevant area of the image as this also reduces the number of fetches from the server.
Describe two ways in which compression can be used to reduce the time taken to retrieve and display a webpage?
- Compression is used when the page is served, thus reducing the amount of data sent to the browser. The browser will decompress the page data when received
- Compression reduces the amount of data exchanged from the server to the browser client, therefore reducing the time taken to load the data
When should a company use beta testing?
Last stage of testing prior to release
