Media Types and Testing

Question 1

Name 2 ways of executing lossless compression with graphics

Answer 1

Run Length Encoding (RLE)

Lempel Ziv Welch (LZW)

Question 2

Is GIF lossy or lossless?

Answer 2

lossless

think GIFless

Question 3

Is JPEG lossy or lossless?

Answer 3

lossy

think JPEGy

Question 4

What are the three steps of JPEG compression?

Answer 4

1. Colour Rep changed
   Resolution Reduced
2. Image split into 8x8 blocks
3. Numeric Value scaled and stored

Question 5

Name techniques of lossy compressing video data

Answer 5

Motion Estimation

Compensation

Question 6

What are the three types of frames stored in a video?

Answer 6

Intra Frames (I) - Full frame (jpeg)
Predicted Frames (P) - previous I frame (predicted)
Bidirectional Frames (B) - interpolated from back and forward frames

Question 7

Name a method of compressing audio

Answer 7

MPEG Layer 3 (MP3)

Question 8

Is MPEG lossy or lossless?

Answer 8

Lossy

think MPEGy

Question 9

Is FLAC lossy or lossless?

Answer 9

lossless

think FLACless

Question 10

Is m4a lossy or lossless?

Answer 10

lossless

think m4aless

Question 11

What is the purpose of scripting?

Answer 11

Increase Functionality of databases

Perform automated tasks that were previously difficult

Question 12

What are the 5 steps for a web server processing PHP files

Answer 12

1. passes HTML file to browser
2. passes PHP file to PHP processor.
3. browser finds tag hands file to PHP module
4. Web server assumes all statements are PHP until
5. Returns HTML code

Question 13

How does a crawler work?

Answer 13

1. Visits pages of your site
2. Indexes the words and contents of site
3. follows links from the pages
4. Some focussed on particular sites

Question 14

Name 7 ways to optimise code

Answer 14

Compressed Images
Link thumbnails to full sized images
Combine Images
Group external CSS files
Combine CSS declarations
Use CSS instructions to show parts of larger images
Abbreviate using hex colours

Question 15

Name 5 methods to control bot indexing

Answer 15

Descriptive title tag
Detailed meta descriptions
robot.txt = cannot access
meta tags to command bots
noindex HTTP header

Question 16

What are the 7 definitions of a usable page?

Answer 16

Useful
Usable
Desirable
Valuable
Accessible
Findable
Credible

Question 17

What are 6 measures that can be taken to evaluate UX?

Answer 17

Successful task rate
Critical/Non-critical errors
Error free rate
Task Times
Likes/Dislikes
Eye Tracking data

Question 18

Name three techniques for evaluating UX

Answer 18

Concurrent Think aloud
Retrospective Think Aloud
Concurrent Probing

Question 19

Name 4 compatibility issues

Answer 19

Memory Requirements
Backing Storage Reqs
Operating Sytem Version
Browser Versions

Question 20

What three things should you think about with purpose of a product?

Answer 20

What must it do?
Who is it for?
What do they want to use the product for?

Question 21

What things must designers think about in terms of user ability of a program?

Answer 21

Pressing multiple buttons while looking at screen
Lots of images to explain things
Ability to memorise

Question 22

What are the three ability groups for target audience?

Answer 22

Novice
Intermediate
Expert

Question 23

Name two advantages of server-side validation of forms

Answer 23

More secure (harder to hack)
Improved compatibility

Question 24

Name two disadvantages of server-side validation of forms

Answer 24

Can increase network traffic with more calls from servers

Responses may be slow and frustrating where bandwidth is poor

Question 25

Describe 3 situations where a syntax error may occur in a database

Answer 25

Query incorrectly formatted Using a formula to perform a calculation Validation rule is incorrectly entered

Question 26

Describe 5 situations where an execution error may occur when reading from a text file

Answer 26

``` Cannot locate file File has no data Read beyond the file Data in wrong order Unreadable format ```

Question 27

State 4 ways server-side validation may be more appropriate than client-side validation

Answer 27

Updating centrally held data no possible with client-side Validation can't be disabled if handled at server Can query SQL using PHP Less security issues

Question 28

State 3 ways code can be optimised to increase load times

Answer 28

CSS file to hold CSS rules = less data delivered Merge JavaScript files = reduced fetches Merge Images = reduced fetches