SPSS MTO-D SAMENVATTING
SESSION 1 RELIABILITY ANALYSIS
ASSIGNMENT 1 TOLERANCE SCALE
VRAAG 2
The tolerance scale consists of 18 statements. For each statement, the participants indicate whether they think
it can always be justified, never be justified, or
something in between. They do so on a scale from 1 to
10:
DK means ‘does not know’, and Na means ‘no answer’.
The statements that were rated by the participants are listed below.
VRAAG 3
Start with running a reliability analysis in SPSS. Go to Analyze→ Scale→ Reliability Analysis, and drag all items of
the tolerance scale (v225 through v242) into the Items window (Hint: Right-click in the Items window and
choose “Display variable names” to get the names of the items).
Click on the Statisticsbutton and enable the following options
before you paste the syntax:
• Item, Scale and Scale if item deleted in Descriptives for
• Correlations in Inter-Item
Click on Continue, and paste and run the syntax. Also paste the
syntax you created in the answer box below.
DATASET ACTIVATE DataSet1.
RELIABILITY
/VARIABLES=v225 v226 v227 v228 v229 v230 v231 v232 v233
v234 v235 v236 v237 v238 v239 v240 v241
v242
/SCALE('ALL VARIABLES') ALL
/MODEL=ALPHA
/STATISTICS=SCALE CORR
/SUMMARY=TOTAL.
,
, VRAAG 4
First you need to check whether you need to reverse code one or more items. Look at the Inter-Item
Correlation Matrix to see whether all items are positively correlated with each other. If one or more items are
negatively correlated with the rest, they are probably formulated in the reversed direction which means you
need to recode them.
Do you have to recode (an) item(s)?
No.
(Kijk in de Inter-Item Correlation matrix, daar staan geen negatieve getallen dat betekent dat er geen contra-
indicatieve vragen zijn die hergecodeerd moeten worden.)
VRAAG 5
In the Reliability Statistics table you can see Cronbach’s alpha, which is an estimation of the reliability of the
scale.
What is the Cronbach’s alpha of the tolerance scale?
.864
(Kijk bij ‘Reliability Statistics’ en dan de Cronbach’s Alpha)
VRAAG 6
Now look at the Item-Total Statistics table and the Inter-Item Correlation Matrix.
• Do all items contribute positively to the reliability of the scale?
• Which item contributes the most to the reliability of the scale?
Eigen antwoord:
Yes, all items contribute positively to the reliability of the scale.
The item having casual sex contributes the most to the reliability scale.
Antwoord: Yes, all items contribute positively to the reliability of the scale – all corrected item-total correlations
are positive and above .3 and Cronbach’s alpha if item deleted is lower than Cronbach’s alpha of the whole
scale (0.864) for all items. The item having causal sex contributes the most to the reliability of the scale: Of all
items, it has the highest corrected item-total correlation and the lowest Cronbach’s alpha if item deleted.
VRAAG 7
Which two items are most related?
Throwing away litter
Speeding over limit
Driving under influence of alcohol
Accepting a bribe
Smoking in public places
Cheating on tax
Having casual sex
Abortion
Claim state benefits
Paying cash
Adultery
Euthanasia
Joyriding
Lying
Suicide
Divorce
Homosexuality
Taking soft drugs
See the correlation matrix: The items that are the most related are Divorce and Abortion (Correlation of 0.679)
SESSION 1 RELIABILITY ANALYSIS
ASSIGNMENT 1 TOLERANCE SCALE
VRAAG 2
The tolerance scale consists of 18 statements. For each statement, the participants indicate whether they think
it can always be justified, never be justified, or
something in between. They do so on a scale from 1 to
10:
DK means ‘does not know’, and Na means ‘no answer’.
The statements that were rated by the participants are listed below.
VRAAG 3
Start with running a reliability analysis in SPSS. Go to Analyze→ Scale→ Reliability Analysis, and drag all items of
the tolerance scale (v225 through v242) into the Items window (Hint: Right-click in the Items window and
choose “Display variable names” to get the names of the items).
Click on the Statisticsbutton and enable the following options
before you paste the syntax:
• Item, Scale and Scale if item deleted in Descriptives for
• Correlations in Inter-Item
Click on Continue, and paste and run the syntax. Also paste the
syntax you created in the answer box below.
DATASET ACTIVATE DataSet1.
RELIABILITY
/VARIABLES=v225 v226 v227 v228 v229 v230 v231 v232 v233
v234 v235 v236 v237 v238 v239 v240 v241
v242
/SCALE('ALL VARIABLES') ALL
/MODEL=ALPHA
/STATISTICS=SCALE CORR
/SUMMARY=TOTAL.
,
, VRAAG 4
First you need to check whether you need to reverse code one or more items. Look at the Inter-Item
Correlation Matrix to see whether all items are positively correlated with each other. If one or more items are
negatively correlated with the rest, they are probably formulated in the reversed direction which means you
need to recode them.
Do you have to recode (an) item(s)?
No.
(Kijk in de Inter-Item Correlation matrix, daar staan geen negatieve getallen dat betekent dat er geen contra-
indicatieve vragen zijn die hergecodeerd moeten worden.)
VRAAG 5
In the Reliability Statistics table you can see Cronbach’s alpha, which is an estimation of the reliability of the
scale.
What is the Cronbach’s alpha of the tolerance scale?
.864
(Kijk bij ‘Reliability Statistics’ en dan de Cronbach’s Alpha)
VRAAG 6
Now look at the Item-Total Statistics table and the Inter-Item Correlation Matrix.
• Do all items contribute positively to the reliability of the scale?
• Which item contributes the most to the reliability of the scale?
Eigen antwoord:
Yes, all items contribute positively to the reliability of the scale.
The item having casual sex contributes the most to the reliability scale.
Antwoord: Yes, all items contribute positively to the reliability of the scale – all corrected item-total correlations
are positive and above .3 and Cronbach’s alpha if item deleted is lower than Cronbach’s alpha of the whole
scale (0.864) for all items. The item having causal sex contributes the most to the reliability of the scale: Of all
items, it has the highest corrected item-total correlation and the lowest Cronbach’s alpha if item deleted.
VRAAG 7
Which two items are most related?
Throwing away litter
Speeding over limit
Driving under influence of alcohol
Accepting a bribe
Smoking in public places
Cheating on tax
Having casual sex
Abortion
Claim state benefits
Paying cash
Adultery
Euthanasia
Joyriding
Lying
Suicide
Divorce
Homosexuality
Taking soft drugs
See the correlation matrix: The items that are the most related are Divorce and Abortion (Correlation of 0.679)
