SADC Course in Statistics

Organising data in a spreadsheet

Module B2 Sessions 9 and 10

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Contents

• Where we are:– Slides 1-18: Overview of Chapter 1 of the SSC

Excel Guide (Practical 1).

• What is to come:– Slides 19-23: Preview of Chapter 2 of the SSC

Excel Guide (Practical 1).– Slides 24-33: Overview of what has been learnt – Slides 34-36: Preview of Chapter 3 of the SSC

Excel Guide (Practical 2).– Slides 36-41: Overview of what has been learnt– Slides 42-48: Introducing Practical 3– Slide 49: Reviewing Practical 3

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So far

• Steps once you have the data• Session 1

• Tables and graphs in Excel• Once the data are well organised

• These sessions• The skills to organise the data• So it is ready for analysis• This often takes as much time as the analysis itself

• Excel has tools to help

• They are introduced here

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What is assumed:

Excel guide Chapter 1.

• See the following slides.

• Check this is all familiar.

• The guide can be used as a reference.

• Review quickly if necessary.

• If you need a more thorough review this must be done in your own time.

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The Windows desktop (1.2): Do you recognise everything?

Start button and menuRecycle bin

my computer

Taskbar showing programs currently open

“Office” software

Statistical software

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Mouse Operations (1.2):

Operation Description

Clicking Move the mouse so the tip of the pointer touches the element you want to use. Then press and release the left mouse button.

Right-clicking Same as the above, but you press and release the right button.

Double-clicking Press and release the left button twice in rapid succession

Dragging Press and hold down the left button. Then, with the button still pressed, move the mouse across the screen. Release the button when you are at your destination.

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Mimimise, maximise and close buttons

My Computer icon on desktop

My Computer icon on the taskbar

Corner or side for dragging

Title bar

Practicing using the mouse (1.2):

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Help command

Help window

Windows Help (1.2):

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Active cell

Worksheet

Sheets, making up a workbook

Column headings

Row headings

Formula bar

Scroll bars

Menu bar

Toolbar

A Typical Excel Window (1.3):

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Click to open the selected file

List of files in the current folder

Selected file

Drop-down list with the folder tree

The Open Files Dialogue (1.4):

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Active sheet

Other sheets in the workbook

Worksheet navigation buttons

Open Workbook in Excel (1.4):

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Paste and paste Special:

• For the next few slides get on your computers and follow along.

• Open the excel workbook: SSC Introduction to handling data in Excel

• Use your Excel guide as a reference, reading the instructions carefully. Chapter One, Section 1.5

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Popup menu for basic operations on active sheet (1.5):

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The cells that were dragged The part where you used CTRL and then dragged

Selecting parts of a worksheet (1.5):

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The Paste Special dialogue (1.5):

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This cell is linked and not just copied as the number 23

Linking information across worksheets (1.5):

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Tooltip to show destination

Pointer is an arrow

Border of new destination

Moving a range of cells (1.5):

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New name for the file

Folder in which the file will be saved

The Save As dialogue (1.5):

SADC Course in Statistics

Handling Data

In Excel

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Chapter 2: Data Manipulation

This chapter looks at the features of excel needed to organise data prior to analysis.

Data sets are often large and messy, organising them can be a bigger job than analysing the data.

Excel has a number of useful tools to make this job as quick and easy as possible.

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Data Manipulation cont’:

Good Practice:You must always try to keep worksheets

simple, to give them names and to clearly show what they contain.

This will make it much easier when you need to find a particular data set or table of results.

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What to expect:

In chapter 2 you will learn:

• How to efficiently structure your data.

• How to create and protect master copies of you data.

• How to create duplicate working copies.

• How to sort your data for easier checking.

• How to select subsets (Filtering).

• How to name cell ranges.

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Practical 1:

• Now go and complete Chapter 2 of the Excel guide.

• Read each point and complete the exercise below when applicable.

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How did it go?

• The next few slides are screen captures taken from the work you have just done.

• Go through them as a class making sure that you understood how to use each tool and its purpose.

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Data from the CBS survey is in list form (2.2):What are the features of a list?What are the benefits of having your data in a list?

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Master Sheets and Working Sheets(2.3-2.4):

• This is a crucial step in your organisation process and should always be the first thing that you do.

Creating your Master Sheet keeps your data SAFE!

Creating your Working Sheet gives you FREEDOM to make mistakes!

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Sort dialogue& Data sorted on household size(2.5):

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Selected rows

Arrow is blue to show it is used in filter.

The filtered data (2.6):

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Fig. 12.1 Applying a custom filter

Applying a custom filter & Options in custom filter dialogue box (2.6)

Fig 12.3 The custom filter dialogue

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Adding a comment to a cell (2.7):

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Fig. 11.5 Using the name of an array

Using the name of an array (2.7):

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Creating names from a selected array (2.7) Fig. 11.5 Creating names from a selected array

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Features, queries and concerns

• What was new, that you liked?

• What was difficult?

• What do you need to practice more?

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Chapter 3:Performing Claculations

This chapter outlines how Excel can be used to do simple and complex calculations with small and large set of data, it has 2 parts:

1. How to use excels formula bar to perform simple arithmetic calculations (3.2).

2. How to use excel as a column calculator (3.3-3.5).

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What to expect:In Chapter 3 you will learn:

• How to do basic calculations in the formula bar.

• How to use excel to do arithmetics and comparisons using cell addresses.

• How to use excel to do arithmetics and comparisons using column names.

• How to use excels inbuilt functions, these can save you time and safeguard against human error.

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Practical 2:

• Now go and complete Chapter 3 of the Excel guide.

• Read each point and complete the exercises below when applicable.

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How did it go?

• The next few slides are screen captures taken from the work you have just done.

• Go through them as a class making sure that you understood how to use each tool and its purpose.

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Entering a logical calculation (3.2)

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Using columns for calculations (3.4):

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Functions Dialogue Box (3.5):

Keep exploring the program. There are a multitude of functions available. If you do not know they exist you will be stuck do them by hand! Its worth a few minutes.

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Features, queries and concerns

• What was new, that you liked?

• What was difficult?

• What do you need to practice more?

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Applying the new tools

• The new tools in Excel• Enable data to be organised ready for the analysis

• Organising the data is a key step• And time must be allowed for this step

• Once the data are organised

• The ideas in Sessions 4 and 5• Show how they can be analysed to produce tables

• And Sessions 6 and 7• Showed how to produce graphs

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Case study – hourly sunshine data

• The data are needed for the solar cooking project

• Introduced in Module B1

• We need to know • The proportion of days with sufficient morning sun• And afternoon sun• For cooking lunch and dinner• And for pasteurising water

• The hourly data were supplied• In Excel• By the Botswana Met Service• And have to be organised for the analysis

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Hourly data as supplied: 1978 - 1997

Top of data file

Almost a list

But each year is separate.

The year is not included in the list

And there are gaps between each year

Data in 1/10 of an hour

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Stages in the organisation process

• Copy to a new sheet – called data• As supplied• But in a list• With another column giving the year number

• Make a third sheet – called working• Data in fractions of an hour• Then totalled to give morning sun• And afternoon sun • To be ready for the analysis

• This is what you repeat• In practical 3

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The data as supplied – but in a list

With a year column added

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The data – ready for analysis

The key variable for the analysis

Sunshine hours from 9am to 1pm

If >3hrs then OK for cooking. > 1hr for pasteurising water

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Practical 3:• Now that you have these tools at you

disposal try them on these data.

• Keep your guide for reference.

• Complete Practical 3.

• Note the new problems that always occur• with real data• but not in textbook datasets!

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Features, queries and concerns

• What was new that you liked?

• What concerns did you have?

• Did you resolve the challenge• An IF statement is• IF(B3>1,O2,””)

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Can you now:

• Explain the importance of a list • for statistical uses of Excel.

• Use special features, • like sorting and filtering.

• Understand how names are used in Excel.

• Perform simple arithmetic calculations• using Excel’s formula bar.

• Use Excel as a column calculator

• Explain the data organisation stage • that precedes an analysis

• Use the Excel guide • with the demonstrations - for self study

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Learning Software

• It is hard to learn software through lectures as practice is the most effective way of developing the necessary skills.

• Most software will come with a tutorial guide and (possibly) some demonstrations – as you have used here.

• Use the skills you learnt today to work independently with these type of resources (i.e. the guide and demonstrations).

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The next session looks at even more resources with Excel

And now the sunshine data are organised. They are analysed in a later session