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Compute and-recode-part-2
1. 1
Compute and Recode for SPSS Ver 20 (DR SEE KIN HAI) (PART 2)
A science teacher wanted to gauge the attitude of students towards science in rural areas of Brunei. He
wanted to know whether there is a significant difference in their attitude towards science by level of
education (i.e. Year 7, 8, 9, 10 or 11 or equivalent of Form 1,2,3,4 or 5), gender (male=1 or female=2)
and ethnic group (Malay=1, Chinese=2, Kadazan / Dusun = 3, Murut=4, Others=5). For this purpose ,
he prepared a questionnaire that consisted of 2 parts: Part A: Respondents’ demographic background,
Part B: Attitude towards science in school assessment questionnaire modified from Germann (1984).
(Likert scale: SD=1, D=2, A=3, SA=4 reverse for negative items, Missing value = 999)
(The following sample showed the response from a student)
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You should enter into your computer as:
Id Form Gender Race Q1 Q2 Q3 Q4 Q5 Q6 Q7 Q8 Q9 Q10 Q11 Q12 Q13 Q14
1 1 1 1 1 2 4 1 2 4 4 3 2 2 4 3 4 999
Similarly enter the data into your computer as follow and saved them in your data file disk.
3. 3
1. Setup your [Variable View] as follow: Missing value
1=Malay, 2=Chinese, 3=Kadazan/Dusun SD=1, D=2, A=3, SA=4
4= Murut, 5=Others
2. Now you enter the data as below.
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3. Now, the items for the questionnaire, Q2, Q7, Q10 and Q14 are negative items so the Likert
scale should be reversed. SD =4, D= 3, A=2 and SA = 1.
4. Now you [Recode] the negatively-worded questions into the [same variables]. If you want can
be into [different variables].
5. Select [Transform] in the menu bar and click [Recode into Same Variables] to open the
dialogue box.
6. Move [Q2, Q7, Q10 , Q14] into the [Variables] box then click [Old and New values] to open
the sub-dialogue box.
7. Enter [1] in the [Old Value] box and [4] in the [New Value] box then [Add]. Repeat for 2 → 3,
3 → 2 and 4 → 1.
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7. Click on [Continue] then [OK]. Now you examine the [Data View] below the scores have been
reversed.
COMPUTE DATA
Now to score students’ attitude towards science, you have to add up the scores for the 14 questions.
There are 2 ways of doing this.
How to total the score for each student in this questionnaire
Method 1: (If you do not want to include the missing items, e.g. Q14)
1. Select [Transform] then [Compute Variable..] to open the dialogue box.
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2. Type [Total] into [Target Variable] box. Move [Q1] then [+] and repeat until [Q14] then [OK].
3. Now click on [Data View], [Total] is created.
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Total is added to the [Variable View]
Total value missing because of 999. To
avoid this use Method 2
Method 2: ( Use the [Function group] if you want to include the missing values, e.g. Q14)
1. Select [Transform] then [Compute Variable..] to open the dialogue box.
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2. Enter [Total] in the [Targer Variable] box. In the [Function group] box select [Statistical] and
[Sum] in the [Functions and Special Variables] box.
3. Click on [ ↑ ] to bring this function into [Numeric Expression] box.
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4. Move [Q1] to [Numeric Expression] box. Repeat until [Q14] then [OK].
5. Now you examine the [Data View] below.
The Total added for the missing values
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How to obtain mean score for each student in this questionnaire
Method 1: (To exclude the missing values)
1. Select [Transform] then [Compute Variable…] to open the dialogue box.
2. Type [Mean] in [Target Variable] box. Select [( )] and move [Q1] to [Q14] into
[Numeric Expression] box then [OK] as follow.
Missing values not included. If you
want to find the mean use Method 2
Method 2: (To include missing values in the calculation of the means)
1. Select [Transform] then [Compute Variable…] to open the dialogue box.
2. Type [Mean] in the [Target Variable] then select[Statistical] and [Mean] in the [Function group]
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3. Click [ ↑ ] and move to [Numeric Expression] box. Move [Q1] to [Q14] into the [Numeric
Expression] box then [OK].
The means are calculated for the missing values
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How to count the the total number of SD, D, A, SA coded as 1,2,3,4 for each student
1. Select [Transform] then [Count Values within Cases…] to open the dialogue box.
2. Enter [No1] in the [Target Variable] box and [Frequency of score 1] in the [Target Label] box.
Move [Q1] to [Q14] into [Numeric Variables] box then click on [Define Values] to open the
sub-dialogue box.
3. Click [1] in the [Value] box then [Add] to move to [Values to count] then [Continue] then [OK].
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4. [Transform] then [Count Values within Cases..] type [No2] and [Frequency for score 2] and
move [Q1] to [Q4] as below. [Define Values..] to open sub-dialogue box.
Type [2] in [Value] box then [Add]and [Continue], [OK].
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5. Repeat for [No3] for [Frequency of score 3] and [No4] for [Frequency of score 4].
Go to [Variable view ] change decimal place =0,
