Introduction

Learning objectives

The learning objectives for this session are that by the end of it you should:

1. know the different methods of data validation;
2. understand that using these methods does not ensure that the data is correct;
3. understand the role of data validation in GCSE, GVNQ and 'A' level specifications.

Return to the top of the page

About this session

Data validation is an important concept in IT which you will have to teach at GCSE, GNVQ and A level. In this session we will focus on the issues involved in teaching this topic at each of these levels. Before the session, you are to answer some typical GCSE and 'A' level questions on the topic. In the session we will discuss your answers and the issues that arise from them.

Return to the top of the page

Products of the session

The products of this session are your answers to the questions set.

Return to the top of the page

The task

In advance of the session, you should answer (on paper) the questions listed below, and bring your answers - and queries about them - to the session. The questions and reading cover the topic at the three levels at which you are likely to have to teach it - GCSE, GNVQ and 'A' level.

GCSE

You should answer questions 7.3-7.8 in Steve McWeeney's book 'Information Technology GCSE' and those on pages 21-22 of his Workbook.

GNVQ

Read the performance indicators in section C4 (3.4) of the Part 1 GNVQ Information Technology booklet and be prepared to discuss what they would mean in practice.

A level

You should read section 11.2 of Steve McWeeney's book for AS module 2 'Information: management and manipulation' and ensure that you can successfully answer all the questions listed in 'Questions 02' of this book.

Return to the top of the page

The timetable

Before the session, you should answer the set questions. We will begin the discussion of your answers at 2:00.

Return to the top of the page

Links to other sessions

You will need to use techniques for data validation in the Excel and Access-based parts of Assignment 1.1 and will need to consider the teaching of these techniques in the sessions where you write plans for lessons in which pupils construct a database and spreadsheet models.

Return to the top of the page

In the classroom

Misconceptions

The major misconception in this topic is of the nature of data validation. Many pupils think that the techniques of data validation ensure that the data are correct. It does not. It does ensure that the data are of the correct kind and range, but not that they are what they should be. It is perhaps best to think of it as a set of techniques for ensuring plausible rather than correct data.

Return to the top of the page

Classroom examples

Spreadsheets

You will find some examples of this on the worksheet initially written by geography colleagues to advise on where to place a camp-site. I adapted this to demonstrate a number of the ways in which Excel can be used to validate data - of course were the worksheet to be used 'for real' it would not contain this variety of different methods.

Word

One way to validate date in Word is to use the Form menu to produce lists of words (or phrases) from which the pupils select. This can be used to produce 'fill-in-the-blanks' worksheets. You could start with the sheets produced by Elizabeth Doyle or Willietta Afadi and change the lists. Note that you need to unlock the forms before you can change the items and then relock the forms in order to use them.

Return to the top of the page

Teaching point

Many BTs find it hard to distinguish between knowing, understanding and being able to do when writing lesson plans. This session should have made things clearer.

Some people understood the concept of data validation but did not know the accepted names of the types.

Others knew the names of the types but did not understand the concept - in particular there was a belief in some people that valid data was correct data.

A further group both understood the concept and knew the types of data validation.

Finally, some members of each of these three groups could 'do' data validation - i.e. implement it it one or more software packages - while others could not.

I hope that this experience will help make the distinction between knowing, understanding and being able to do much clearer. You need to think carefully which you want pupils to learn - knowing, understanding or doing (you can of course have more than one) and then design activities to help them learn this - and to help you know whether they have learnt it.

Return to the top of the page

Other Resources

The DfEE Schemes of Work

You should look at the following units of the DfEE schemes of work:

Key Stage 2: unit 5C, Evaluating information, checking accuracy and questioning plausibility;

Key Stage 3: unit 14, Global communication - negotiating and transferring data.

Return to the top of the page

Books/Papers

In this session you have used the GCSE and 'A' level books by McWeeney. These and their associated support materials can be downloaded from the GCSE and 'A' level sections of the course web site respectively. Note that from the GCSE section you can also download all the files for a linked practical course for GCSE by the same author.

For more help in implementing data validation techniques in Word, Excel and Access see the relevant book in the 'Successful ICT projects in ..." series by Heathcote. The tutorials on the software resources page will also provide help.

Return to the top of the page