Evaluating
data for
fitness
for
purpose,
accuracy
and bias
GIGO
Abbreviation for
garbage in
garbage out. It
means if you
out rubbish in
the computer -
then you get
rubbish out.
Data
Raw
facts
and
figures
with no
meaning,
e.g.
readings
from
sensors
and
survey
facts,
etc.
Data
can be
numbers,
words,
images,
sound.
Processing
Data is
processed by a
computer.
Performing
calculations or
arranging the
data into a
meaningful order.
Eg. Working out
an athlete's
average age over
3 tears.
Information
Data that has
been been
processed by
the computer.
Data + Meaning + Context = Information
Knowledge
Derived from information by
applying rules to it. Knowledge
is the application of
information to a situation.
Example -
99 = Data,
£99 price of
tv =
information, I
only have
£90
therefore I
do not have
enough
money to
buy this tv
Encoding
and the
storage of
data
Encoding
Assigning
codes to
the data,
reducing it's
size.
E.g - Size
of clothes
- S =
Small, M =
Medium, L
= Large.
E.g - Airport
codes - LHR
= London
Heathrow,
MAN =
Manchester.
Advantages
Takes up
less storage
space, easily
transferable,
easier to
back.
Disadvantages
Easily
stolen,
training
needed,
security
problems,
viruses
etc.
Data Validation
Transcription error
Error made
when typing in
data using a
document as
the source of
the data. E.g -
Mishearing
what a person
says over the
phone and
entering it into
the computer.
Presence Check
Is used to check that data is entered is entered into the correct fields. E.g
- Entering your username and password into facebook.
Transposition error
Error
made
when
characters
are
swapped
around so
they are
in the
wrong
order. E.g
- putting
in
faceboko
instead of
facebook
validation Checks
Are checks a developer of a solution sets/ creates, using the software, in order to
restrict the data that a user can enter, so as to reduce errors. Presence and range
checks are validation check examples.
Check digit
A decimal
number (or an
alphanumeric
character) added
to a number for
the purpose of
detecting the
sorts of errors
that humans
normally make on
a data entry. E.g
- Account
numbers will have
check digits, to
check that the
numbers inputted
are correct.
Range
check
Data validation
technique which
checks that the
data input to a
computer is within
a certain range. E.g
- checking the data
of birth of a year 9
pupil is lower than
1998, since the
system wouldn't
allow that person to
enter that date as
they are too old for
year 9.
Data verification
Batch total
A meaningful total
that is used to check
that the computer has
input all the data. E.g
- adding up all the
totals of a batch of
sold ebay items.
Hatch total
Meaningless total
of numbers, such
as order numbers,
used to check
that all the data
has been entered.
Parity check
Check to make sure that the data
sent is the same as that recieved
when data is transmitted from one
computer to another. E.g - An email
sent from one person to another.
Verification
Checking that the data
being entered into the
ICT system perfectly
matches the source of
the data. E.g - Checking
the text/ data in an
email and making sure
when it arrives to the
recipient that no error
has been introduced.