Data Types and Storing Data
Types of Data
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Text
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Numeric
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Can only be numbers. Can be whole or decimal. Can be formatted
eg 345.6789 formatted to two decimal places = 345.67, formatted
to currency = £345.67.
Date/Time
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Allows input of any letter, number, space, punctuation mark or
special character like £ % & etc. Cannot do calculations with
numbers stored as text.
Must only have days, months years and time format. Can be
different layouts eg dd/mm/yy or dd/mm/yyyy
Boolean
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Can only have two values; true or false (eg Yes/No)
Types of Data
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When setting up a database of pupil records we may decide on
the following fields:
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Pupil registration number
Forename
Surname
DOB
House Number
Street Name
Town
County
Postcode
School Meals
Types of Data
Pupil
No
Forename
Surname
DOB
Postcode
School
Meals
23
Alice
Brown
14/12/89
WG12 3BR
Yes
29
Molly
Reece
12/09/88
WG12 4XV
Yes
54
Brian
Trimble
05/05/90
NE1 34Z
No
77
Vivien
Jones
07/06/90
NE7 33X
No
88
Peter
Martinez
08/04/90
NE8 44Q
Yes
Storing Data
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One of the most important uses of
computers is for storing and analysing
data. For the computer to give you
accurate information, you first have to
input accurate data.
One way of collecting data is to use a
questionnaire.
Collecting Data
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Observation is the best method to use if you
want precise numbers.
Interviewing is the best method to use if you
want a wide range of ideas and comments.
Questionnaires are a good way of collecting
data when you are trying to find out facts
that require no additional explanation.
Collecting Data
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For each situation decide whether a questionnaire,
observation or an interview would be the best way of
collecting the data.
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Finding out customers’ opinions about the taste of a new dessert.
Logging the number of lorries that pass the entrance to a primary
school.
Collecting information about sporting activities.
Collecting ideas from pupils for fund-raising events.
Recording the number of males and females buying clothes from a
store and collecting data about their purchases.
Finding out whether a person is the best candidate for a job.
Designing a Questionnaire
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Decide what you want to know.
Decide who you will give the
questionnaire to.
Write the first draft of your questions.
Writing the Questions
1.
2.
3.
4.
5.
6.
7.
8.
What is your name?
How old are you?
What are your hobbies?
How often do you play sports?
When were you born?
How much do you spend on leisure
activities each week?
Which school do you attend?
What are your favourite leisure activities?
Things to Remember When
Writing Questions
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Avoid asking the same thing twice.
Avoid sensitive or embarrassing questions.
How easy is it to answer the question. Give boxes to
tick, where appropriate.
For quantities, how accurate do the answers need to
be?
Should the question be open or closed?
Restrict the range of possible answers by giving a list.
Use ranking to find out people’s preferences.
Avoid biased questions.
The Final Version
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Questionnaires should be neatly produced
with no typing or spelling errors.
There should be a short introduction
explaining who the questionnaire is for and
why they want the information. Use a
different typeface for this so it stands out
from the questions on the sheet.
The questionnaire should be as short as
possible, so you don’t waste people’s time.
The Final Version Cont …
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The order of the questions is important. Start
with closed questions that are easy to
answer. Next ask any more complex
questions and finally more personal
questions. This way people are more likely to
complete your questionnaire.
Provide enough space for the answers.
Add a note at the bottom of the questionnaire
to say thank you. Always be polite – you
never know when you will need to ask them
again.
The Final Version Cont…
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Finally, give your questionnaire to a
friend to complete. What do you think?
Does anything distract you? Are the
questions clear?
Questions
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Reword these questions so that they can be
answered as accurately as possible:
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How old is your eldest child?
How much frozen food do you buy from the supermarket?
How many miles do you walk every week?
Do you wash as well as cook at home?
In which age category are you?
Teenager/Middle aged/Pensioner
Explain what we mean by a ‘closed’ question.
Why do you think closed questions make people feel
more comfortable at the start of a questionnaire?