2. Learning objectives
•When you have finished this topic you will
be able to:
i. To define data
ii. Relate data and information
iii.Explain the distinction between data and
information
iv.Identify sources of information
PRESBYTERIAN SEMINARY . FORM 1. 2018 2
3. Cont…
i. State the importance of information
ii. List traditional and modern ways of
disseminating information
iii.Explain communication media
iv.Describe the difference between analogue
and digital data
v. Name two types of input checks: verification
and validation
PRESBYTERIAN SEMINARY . FORM 1. 2018 3
4. Data
• What is data?
• Data is raw facts that doesn’t mean very much to user
. Data may include numbers,letters and symbols.
• Most of the time data is stored as coded data, which
we human beings would find difficult to understand
anyway.
Example of data includes
14,20,John,Boy,Girl,true,False etc.
PRESBYTERIAN SEMINARY . FORM 1. 2018 4
5. Data types
•For this level we are only concern with five type of data
which are :
i. Number
Number includes whole numbers which do not contain
decimals( the proper name for them is “Integer”).
The other number are those that include decimal(these
are called “reals”).
Integers are used for things like a person’s age, whereas
a real would have to be used for their height.
PRESBYTERIAN SEMINARY . FORM 1. 2018 5
6. Cont…
•Currency
This used to tell computer that the data is a real
number that has a limit of two decimal places and
will have a unit with it such as $,€, £, Tshs.
•Date
This type of data display date example : 23rd may
1990, 1st January 2018.
PRESBYTERIAN SEMINARY . FORM 1. 2018 6
7. •Text : this consist of characters from the
keyboard has no hidden meaning.
Text is also called alphanumeric since sometime
can combine letters and numbers.
When it is one letter is called a character example
M or F
•Boolean data: the Boolean data type is a data
type, having two values (usually denoted true
and false) or Yes and No
PRESBYTERIAN SEMINARY . FORM 1. 2018 7
8. Analogue data and digital data
•Analogue data is physical data and can have any
value.
•Analogue data are represented using a
continuous waveform.
Example of analogue data is sound.
PRESBYTERIAN SEMINARY . FORM 1. 2018 8
9. •All analogue devices use analogue data.
Examples of analogue devices include:
•Microphone
•Headphones
•Loud Speaker
•Sensors (temperature, pressure etc.)
PRESBYTERIAN SEMINARY . FORM 1. 2018 9
10. •Digital data :
is usually represented using two-state square
waveform.
•All digital devices use digital data. Examples of digital
devices include:
Computers/Laptops/IPads
Mobile Phone
MP3 Player
Digital Camera
PRESBYTERIAN SEMINARY . FORM 1. 2018 10
11. •The name "Digital" is given to all devices that
store and process data in the form of 'digits'
(numbers).
•These digits are known as 'Binary'.
PRESBYTERIAN SEMINARY . FORM 1. 2018 11
12. Data input and checking
•When data is input to a computer system, it is
important to make sure that no errors are made.
•There are two types of checking that should be
done on data input to a system.
Data verification and
Data validation
They sound very similar but are actually totally
different.
PRESBYTERIAN SEMINARY . FORM 1. 2018 12
13. •Data verification:
Data verification is a way of ensuring the user
types in what he or she intends.
•In other words, to make sure the user does not
make a mistake when inputting data.
•Data validation:
Data validation is the process of comparing data
with a set of rules to find out if data is reasonable.
PRESBYTERIAN SEMINARY . FORM 1. 2018 13
14. Information
•Information is a processed data.
•When data is processed, organized, structured or
presented in a given context so as to make it
useful, it is called information.
•Therefore information is data in a context that
gives it meaning.
PRESBYTERIAN SEMINARY . FORM 1. 2018 14
15. Distinction between data and information
Data Information
1. Data is used as input for the
computer system.
2. Data is unprocessed facts figures
3. Data doesn’t depend on
Information.
4. Data is not specific.
5. Data is a single unit.
6. Data doesn’t carry a meaning.
7. Data is the raw material.
1. Information is the output of data.
2. Information is processed data.
3. Information depends on data.
4. Information is specific.
5. A group of data which carries
news and meaning is called
Information.
6. Information must carry a logical
meaning.
7. Information is the product.PRESBYTERIAN SEMINARY . FORM 1. 2018 15
