Make your codebook

This example is based on a market research project. In this project a questionnaire went out and we got a lot of data back from our respondents. To have a guideline when filling in your data, using a codebook is very handy. In fact, it is essential if someone else is filling in data for you. Below you can find an explanation on how to make this codebook.

1. Make a copy of your questionnaire document, and name it e.g. codebook.doc (a little obvious, I know).
2. Change the question numbers into variable names. The most logical thing to do is to give question 1 the variable name q1, question 2 the variable name q2, etc.

2 comments May 10th, 2006 andris

How to obtain subgroup Means

Many visitors of our blog are searching for information about the one sample t-test.

From the menus choose: Analyze>Compare Means>Means

Select one or more dependent variables.Use one of the following methods to select categorical independent variables:

Select one or more independent variables. Separate results are displayed for each independent variable.
Select one or more layers of independent variables. Each layer further subdivides the sample. If you have one independent variable in Layer 1 and one independent variable in Layer 2, the results are displayed in one crossed table, as opposed to separate tables for each independent variable.

Add comment May 8th, 2006 mark

Importing data from an ASCII file

First refer to Importing data into SPSS. If you have read it, than you can continue below.
Typically, columns of data in an ASCII file are separated by a space, tab, comma, or some other character. SPSS has a Text Import Wizard that will help you import data in an ASCII file format:

1. Select File -> Open -> Data
2. Choose Text as the File Type if your ASCII file has the .txt extension. Otherwise you could choose the option All files
3. Select the file you want to import and click Open

3 comments May 3rd, 2006 andris

Import data from an Excel file

First refer to Importing data into SPSS. If you have read it, than you can continue below.
Before you start the actual import process, please keep in mind that the Excel file should not be opened in Excel.

1. Select File -> Open -> Data
2. Choose Excel as the File Type
3. Select the file you want to import and click Open

 

3 comments May 3rd, 2006 andris

Nominal, ordinal and scale

Today Erik from the Netherlands sent us the following question:

What is the diffrence between nominal, ordinal and scale?

In SPSS you can specify the level of measurement as scale (numeric data on an interval or ratio scale), ordinal, or nominal. Nominal and ordinal data can be either string alphanumeric) or numeric.But what is the difference?

Nominal.
A variable can be treated as nominal when its values represent categories with no intrinsic ranking; for example, the department of the company in which an employee works. Examples of nominal variables include region, zip code, or religious affiliation.A variable can be treated as nominal when its values represent categories with no intrinsic ranking; for example, the department of the company in which an employee works. Examples of nominal variables include region, zip code, or religious affiliation.

6 comments May 3rd, 2006 mark

Import data from a tab delimited text file

First refer to Importing data into SPSS. If you have read it, than you can continue below.

1. Select File -> Open -> Data
2. Choose Text as the File Type
3. Select the file you want to import and click Open

4. The next thing that will pop up is the Import text wizard. First click Next if your file does not match a predefined format. It probably doesn’t, so click Next. :) 

5. In step 2, you can set the first question to Delimited. In the second question you choose wether you have a header row or not (are variables names included in the top of the file). After setting the options right, choose Next.

2 comments May 3rd, 2006 andris

Importing data into SPSS

Importing some data

If you have a small amount of data you want to get into SPSS, the most easy way is to simply Copy Paste it into SPSS. Be aware to check if everything ends up in the right cell, and if  you really have all the data you need. The most safe way to get this data into SPSS, would be to import it. Especially if you have a lot of data.

Importing a lot of data

5 comments May 3rd, 2006 andris

How to handle multiple response questions

In a lot of research, multiple answers can be given to a single question. For example:

“What kind of food do you like?”
o soup
o rice
o salad

How do you analyse this type of question? Let’s assume you want to make a table with the answers. How do you combine them? Even though it may seem like the most easy thing to do, this is pretty difficult stuff. SPSS is good at analyzing unique combinations of variables (answers to questions) combined with unique cases (people in a survey). The combination of more than one answer per person, does not fit into that logic. So we have to be a little creative.

18 comments May 2nd, 2006 mark

Entering data in SPSS

We write this post assuming that you have already defined your variables, and that you have not already entered data in another program. If you have, please refer to the post about importing data into SPSS.

Open your SPSS file, and make sure that the tab selected in the bottom is the “Data View” tab. In this view, the rows represent the observations (or respondents, cases) and the columns represent your variables.

1 comment May 1st, 2006 andris

How to define your variables

Start SPSS, and create a new data file (Choose Type in data in the first dialog window). You now see a file that looks like a Microsoft Excel file. In the bottom of your screen, you see two tabs. We see that the tab “Data View” is selected. This is the place to type in your data. Before we take that step, we have to define our variables. Next to the tab “Data View” we see the tab “Variable View“, click on that tab. When you have clicked this tab, you get the following screen:

(click on thumbnail to get the big version)

2 comments April 29th, 2006 andris