Data Types and Storing Data. Types of Data Text Allows input of any letter, number, space, punctuation mark or special character like £ % & etc. Cannot.

Data Types and Storing Data

Types of Data Text

Allows input of any letter, number, space, punctuation mark or special character like £ % & etc. Cannot do calculations with numbers stored as text.

Numeric 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 Must only have days, months years and time format. Can

be different layouts eg dd/mm/yy or dd/mm/yyyy Boolean

Can only have two values; true or false (eg Yes/No)

Types of Data When setting up a database of pupil records we may

decide on the following fields:

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

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 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 For each situation decide whether a

questionnaire, observation or an interview would be the best way of collecting the data.

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

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. What is your name?2. How old are you?3. What are your hobbies?4. How often do you play sports?5. When were you born?6. How much do you spend on leisure

activities each week?7. Which school do you attend?8. What are your favourite leisure

activities?

Things to Remember When Writing Questions 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 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 … 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…

Finally, give your questionnaire to a friend to complete. What do you think? Does anything distract you? Are the questions clear?

Questions Reword these questions so that they can be

answered as accurately as possible: 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?