stuff 4 2morrow

Question 1

what is decomposition?

Answer 1

breaking down a complex problem into smaller problems

Question 2

What is abstractation?

Answer 2

hiding or removing irrelevant details from a problem to reduce the complexity

Question 3

flowchart process shape

Answer 3

rect

Question 4

flowchart input output shape

Answer 4

parralelogram

Question 5

flowchart decision shape

Answer 5

diamond

Question 6

flowchart terminal shape

Answer 6

rounded rect

Question 7

purpose of a truth table

Answer 7

To show all possible inputs and the dependant output

Question 8

what is count controlled iteration

Answer 8

Count-controlled
iteration repeatedly executes a section of code a fixed number of predetermined times.

Question 9

what is condition controlled iteration?

Answer 9

Condition-controlled
iteration
repeatedly executes a section of code until a condition is met - or no longer met.

Question 10

what is pseudocode

Answer 10

. Instead, it is a simple way of describing a set of programming
instructions
in a manner that resembles a programming language.

Question 11

advantages of pseudocode

Answer 11

can be easily converted to an actual programming language as it’s similar to a real language
easy to understand
syntax errors don’t matter
changes can be incorporated quite easily

Question 12

disadvantages to pseudocode

Answer 12

can be hard to see how programs flows
takes time

Question 13

describe how transistors can store a value in binary

Answer 13

Transistor has two states
1 represents on, 0 represents off
each stores 1 bit
Multiple transistors can store a binary value

Question 14

Why is “hexadecimal uses less storage” incorrect?

Answer 14

• Data cannot be stored in hexadecimal // all data is
  stored in binary // hexadecimal is a shortcut for
  computer scientists

Question 15

describe the data that is recorded when the sound is sampled

Answer 15

The height / amplitude…
* …as a numerical value
* …of the wave(form)

Question 16

what is algorithmic thinking?

Answer 16

• …set out the steps needed to solve the problem //
  represented in a flow chart / as pseudocode

Question 17

what is input sanitisation?

Answer 17

cleaning up data entered by removing non standard characters

Question 18

explain the purpose of testing [the vending machine]

Answer 18

cheks it meets user requirements
detect logic/syntax errors
check program does not crash
allow error to be fixed
so no errors when released

Question 19

Give two reasons why computer scientists use hexadecimal to represent numbers instead of
binary.

Answer 19

less chance of input error
easy to convert between hex+binary
easier to communicate/read/remember/enter/write

Question 20

What is image resolution?

Answer 20

number of pixels/height and width of image

Question 21

what is metadata?

Answer 21

data about data/the file/properties of the file

Question 22

why are trace tables useful?

Answer 22

they enable programmers to compare what the value of each variable should be against what a program actually produces.