Practical 1: Introduction to UK Survey Data for studying attitudes … · 2013. 9. 9. · 1....
Transcript of Practical 1: Introduction to UK Survey Data for studying attitudes … · 2013. 9. 9. · 1....
Introduction to UK Survey Data for studying attitudes Practical session 1: Repeated cross‐sectional data The British Social Attitudes Survey 2010
Using the British Social Attitudes Survey 2010
Introduction to UK Survey Data for studying attitudes: Practical Session 1
Contents
1. Exploring documentation online
2. Using Nesstar to explore data online
3. Working with data using SPSS 20 4. Fill in the blanks!
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1. Exploring documentation online
This section examines the documentation and other useful features on the ESDS website for the British Social Attitudes Survey (BSA) 2010. In order to be a critical researcher it is important to understand where the data come from. The documentation that comes with the dataset will help a little, but it will also help to look at how the original dataset was created. Each ESDS dataset has a UK Data Archive catalogue entry and may also have a fuller web page. Through these, you can access data and the documentation. 1.1 Finding the web‐pages on the ESDS site
Start by opening the main ESDS page (www.esds.ac.uk). The easiest way to access the pages about ESDS Government data from this page is to follow the major studies link on the left of the page – see below:
This leads you to a list of the main ESDS datasets. Follow the links to the dataset you are interested in, here, the British Social Attitudes Survey 2010. 1.2 Survey summary information and documentation page
You should open a page that looks like this:
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Web‐page: http://www.esds.ac.uk/findingData/snDescription.asp?sn=6969 ESDS provides a page of basic information for each survey with the same format. The information on this page includes the Principal Investigator(s), Main Topics, Coverage and Methodology as well as lots of other information. Scroll down the BSA 2010 page to see what is available. At the bottom of the page there are links to user guide(s) and/or questionnaire(s) and other information provided by the data supplier. These give more detailed information you need to understand the data: for example about each of the variables, the questionnaires used, how the sampling was done and which weights to use.
If you are registered with ESDS, you can click on the link near the top on the right of this page to download the BSA 2010 (but don’t do this now as we will provide you with the data to use). 1.3 Information about survey series and variable search and other useful links
In addition, surveys supported by ESDS ‐ the large‐scale government‐commissioned surveys ‐ have a survey series page with links that give advice about FAQs (Frequently Asked Questions) for that survey and Starting Analysis, links to publications using that survey and a Variables Search facility. From the BSA 2010 page you are on now, scroll to the top and follow the link to the ESDS BSA web‐pages in the blue box on the right of the page. You should reach this page:
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Note the useful links on the left including:
Datasets: links to the BSA datasets
Starting Analysis: advice on using the BSA for analysis
Variables Search: allows users to do a word search for variables in all BSA datasets or in all the ESDS datasets.
FAQs: Frequently asked questions about the BSA
To move back to the BSA 2010 page, either click the back button in your browser or you can use the Datasets link. 1.4 Exercise
Now using the pages you have just looked at, find the following information about the BSA survey: Look at the BSA 2010 page: Who are the Principal Investigator(s) and Data Collector(s) for this survey?
What was the sample size in 2010 (look at the Methodology section)?
Go to the documentation at the bottom of this page, open the user guide and search it – you can do a word search either using control‐F or by using the search box provided. Then: What are the response options for:
Who should pay for road use?
What the most useful thing the Government could do to make homes more affordable?
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2. Using Nesstar to explore data online
2. Using Nesstar to explore data online
This worksheet demonstrates NesstarThis worksheet demonstrates Nesstari which is an online data discovery and exploration tool used by a number of data archives including the UK Data Archive/ESDS. 2.1 Accessing the survey data online (freely without registering)
Nesstar allows you to explore the data online before registering. From the BSA 2010 webpage, follow the link to Nesstar near the top, right of the screen beside the download/order link.
When Nesstar opens, you should see the following page:
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The left window contains a list of surveys, and the right window contains general information about the BSA.
2.2 Variable information in Nesstar
In the left window, if you click on the signs, you open a new list. For example, if you click
on the by Variable Description under the British Social Attitudes Survey, 2010, you will see a list of variables categories for the BSA 2010.
Click on Housing to find a list of statements or questions.
Click on the first in the list: ‘Would you support or oppose more homes being built in your local area? :Q499’. You will see information about that variable in the right hand window as shown below:
2.3 Further things to do in Nesstar once registered with ESDS
Nesstar can run cross‐tabulations of variables and conduct simple analyses. To use these features, you must be registered with ESDS. For this workshop, we have provided you with a temporary username and password which you will be asked for when you try to add variables to the table. Tabulations Click on the ‘TABULATION’ tab at the top of the screen. To populate the table, click on a variable in the left window and choose ‘add to row’ or ‘add to column’. For example, you can click on ‘Would you support or oppose more homes being built in your local area? :Q499’ and select ‘Add to row’. You will be asked for your username and password at this point. Log in via the ‘UK Federation’ and then select ‘UK Data Archive’ from the list in the drop‐down box to use the
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temporary login we have provided for this workshop. (In real life, you will need your own personal login which you obtain by registering with ESDS). When you are logged in, the table will appear with the variable you selected in it.
Try adding the sex of the respondent to the table as a column. which is found under ‘Household Grid’ and ‘relationship variables’ as a column. You can find this variable in the ‘Person 1 SEX: Q48’ Household Grid and then Relationship Variables – Persons 1‐7 list of variables. This is what you should see:
Do men and women have the same ideas about whether new homes should be built in their area? Are these results what you would expect to see?
Using weights in Nesstar
Along the top on the right are a number of icons. If you hover over each with the mouse, you can see what they are for. These icons allow you to apply a weight from the data set to a tabulation or analysis, to filter the data, to send the tabulation to an Excel spreadsheet and to create a graph of the data, amongst others.
The frequencies displayed in the table your created are the raw statistics for these variables but the BSA should be weighted to ensure the results are unbiased.
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Click on the scales symbol on the top right hand side of the screen.
This brings up a screen which lists all weighting variables associated with the dataset. Select WtFactor and move it to the right hand window using the arrow, and press OK. Note that the words “Weight is on” now appears under the table.
Can you spot any differences between the percentages given in this table and those you produced earlier without weights?
Now that the data are weighted, you are able to report the percentages (and the counts on which they were based) in your research. Exporting data to Excel
You can also easily export the table to Excel:
Click on the Excel icon on the top right hand side of the screen.
Click on Open to open the file – or click on Save, and then save the file with an appropriate name to an appropriate location.
You can also amend the Excel file to produce a suitable table or chart for inclusion in your research.
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Graphs in Nesstar
You can produce graphs in Nesstar by clicking on the chart button and choosing from the five types of chart to produce a graph of the information in your table (see the screenshot below for an example of a graph in Nesstar).
Downloading data or a subset of the data from Nesstar
If you are a registered user you are able to download all, or a selected subset of, the data. Nesstar can save data into formats suitable for SPSS, STATA, SAS, Statistica, DIF (suitable for use in Excel), Dbase and NSDStat formats. You could start to do this by clicking on the disk
icon ‐ but don’t do this now as we are going to give you the data for the exercises.
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3. Working with data in SPSS
This section uses data from the British Social Attitudes Survey 2010 and involves:
creating a frequency table
weighting the data
creating a cross‐tabulation
recoding variables Follow the instructions to see what SPSS 20 looks like and use the drop‐down menus to look at descriptions of the data and to do some simple analyses. 3.1 About SPSS
Open SPSS version 20 (via Start > 2008 > MHS > All). Then open the data (using the standard windows open button): the file we will use is called bsa2010.sav. There are two ways to view the data: in the Data View or the Variable View tabs. The tabs to switch between the two are at the bottom left of the screen. Ensure the Variable View tab (bottom left of screen) is clicked. In Variable View:
Each row represents something that varies between respondents (known as a variable) and each column provides information about the variable including the name, label and coding information in the Values column.
Click on the Data View tab (bottom left of screen). In Data View:
Each column represents a variable in the survey. This is often a response to a question or derived from answers to a question or several questions.
Each row represents an individual respondent
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In both views, you can use the drop‐down menus at the top of the page (i.e. File, Edit, View, Data, Analyze, Graphs etc.) to manipulate the data and to do analyses. The menus used in this section are:
Analyze: Descriptive Statistics: Frequencies…
Data: Weight cases…
Analyze: Descriptive Statistics: Crosstabs… When you conduct an analysis, you see them in the Output window. You can move between the Output window and the data in Data View or Variable View windows, by clicking on the tab in the Taskbar (the bar that is always at the bottom of the screen). 3.2 To create a one‐way frequency table of a variable
From the menu bar at the top of the page, use: Analyze> Descriptive Statistics> Frequencies We will look at a measure of general opinion about same sex relations. Use the Analyze drop‐down menu to open the Frequencies dialogue box. When you get to the Frequencies screen: Select the variable for general opinion about same sex relationships: HomoSex from the list and move it into the right hand box. See below for how this should look. When you have finished, click on ‘OK’.
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Another Output window will now open. You should see the frequency table shown below displayed in this window:
3.3 To weight the data
Use: Data> Weight Cases… Using the drop‐down menus, go to the Weight Cases screen and add the weight WtFactor, then click ‘OK’.
Redo the frequency table for HomoSex and you will see that the percentages have changed a bit. The previous frequency table showed the numbers of households sampled for the survey. The weighted results are the ones that you would report in your research. 3.4 To create a cross‐tabulation
Use: Analyse> Descriptive Statistics> Crosstabs… We will look at satisfaction with area by age group. To create the cross‐tabulation using the drop‐down menus:
Click on: Analyze, Descriptive Statistics, Crosstabs…
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Select HomoSex as your row variable and RSex (gender of respondent) as your column variable (see below for how the Crosstabs box should look)
Click on the Cells… button and select row percentages (you can leave observed ticked too, to keep frequencies)
Click Continue to return to the Crosstabs dialogue box and press OK to run You should see the following cross‐tab in the output window:
We can interpret the first cell in the first column of the table as meaning that among those who think same sex sexual relations are ‘always wrong’, 61.1% are men, while among those who thing they aren’t wrong at all, 44.7% are men.
3.5 Missing values and recoding
We sometime want to alter the way the variable is coded to do analyses. Sometimes this is because a variable has missing data (data that was either not asked to all respondents (normally “not applicable”) or for which some respondents did not give a response (e.g. “Don’t know”). You can see an example by looking at the variable: HomoSex. For missing values, we can go to the Variable View of the data and in the column ‘missing’ declared for that variable the values of missing data as missing i.e. “don’t know” declare for HomoSex that 8 and 9 are missing values. SPSS will then be aware that those values are not valid data and so will not use the cases with those values in analyses. Alternatively, we may also want to combine some categories together, e.g. combine “rarely wrong” and “Not at all wrong” categories in variable HomoSex. To do this in SPSS, use Transform > Recode to different variables Always recode to different variables (so that you can compare your new variable with the original to make sure that the coding worked as you expected).
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4. Fill in the blanks!
In this section there are some pages from chapters from a report published by NatCen giving some key results from the British Social Attitudes Survey 2010.
1. Have a guess at the missing percentages (!) 2. Use the BSA 2010 data in SPSS to fill in the blanks.
If you can’t immediately see the relevant variable in the dataset, you’ll need to look in the BSA documentation online at www.esds.ac.uk. Try searching the questionnaire to find the name of the relevant variable.
You can find the answers by looking at the report online. A link to the report is at the end of this worksheet.
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You can check your answers in the report on the NatCen website or by following the link to the pdf below... http://ir2.flife.de/data/natcen‐social‐research/igb_html/pdf/1000001_e.pdf
i http://nesstar.esds.ac.uk/webview
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