PSYCH 301: Reliability Analysis of Sympathetic Magic Scale Data

This assignment analyzes the reliability of a Sympathetic Magic Scale designed to measure the irrational connection of items believed to lead to harm or pleasure. The analysis utilizes SPSS software to calculate Cronbach's Alpha, a measure of internal consistency. The student begins by calculating the initial Cronbach's Alpha for all items. Subsequently, items with low reliability are systematically removed from the analysis, and the Cronbach's Alpha is recalculated after each removal. The student describes the rationale for removing specific items and explains the impact of item removal on the overall reliability of the scale. The assignment also includes a discussion of the potential limitations of relying solely on internal consistency measures, recognizing that while maximizing Cronbach's Alpha is important, it shouldn't be the only criterion for variable selection as some variables, although not contributing to internal consistency, might be important for the overall research. The analysis includes the output file (.spv) and a Word document detailing the steps and findings.

Analysis
Results from the Cronbach’s Alpha
The Cronbach’s alpha for all the variables included in the analysis is shown in the table below.
Reliability Statistics
Cronbach's
Alpha
N of Items
.835 31
The results show that the cronbach alpha is 0.835. The value of cronbach’s alpha between 0.8
and 0.9 is considered as the good value. In other words, there is internal consistency in the data
collected and it measure the variable for which the data has been collected.
SPSS also allows the researcher to find out, the value of cronchbach alpha if some of the
variables are deleted which have low internal consistency. The result for such variables are
shown in the table below with the value of cronbach if that variable is removed.
Item-Total Statistics
Scale Mean if
Item Deleted
Scale
Variance if
Item Deleted
Corrected
Item-Total
Correlation
Cronbach's
Alpha if Item
Deleted
1 How distressed
would you be to drink a
glass of water, which
has been scientifically
treated, but was
originally wastewater
from showers and
toilets?
88.64 314.864 .388 .829
2 How distressed do
you feel sticking your
hand into the toilet
water to grab your
wallet?
88.82 313.732 .409 .829

3 How distressed do
you feel using this
video camera that a
child pornographer
used?
88.15 309.500 .450 .827
4 How distressed do
you feel using that
knife that was used to
stab somebody?
87.51 306.954 .557 .824
5 How distressed do
you feel sleeping in that
bed?
88.04 305.968 .567 .824
6 How distressed do
you feel being in the
bath?
88.11 304.429 .599 .823
7 How distressed do
you feel sitting in that
movie seat?
88.06 302.706 .619 .822
8 How distressed do
you feel listening to this
music that inspired
Hitler?
88.80 305.580 .521 .825
9 How distressed do
you feel eating one of
the untouched cookies?
88.48 304.743 .487 .825
10 How distressed do
you feel purchasing this
photograph?
88.12 310.929 .441 .828
11 How distressed do
you feel having your
operation in this room?
88.30 306.510 .489 .826
12 How distressed do
you feel swimming in
the pool with a person
who has HIV/AIDS?
88.37 307.620 .458 .827
13 How distressed do
you feel moving into
the office where
someone died?
89.07 311.017 .506 .826

14 How distressed do
you feel boarding your
flight?
88.14 304.151 .567 .823
15 How distressed do
you feel wearing these
clothes?
88.58 310.328 .461 .827
16 How distressed do
you feel NOT touching
the doorframe as you
walk out of your home?
87.57 347.952 -.264 .854
17 How pleased are
you to receive this
personal item?
89.38 347.678 -.268 .853
18 How pleased are
you to use this pen
while taking your test?
88.78 318.717 .261 .833
19 How distressed are
you to shake their
hand?
88.23 303.695 .549 .824
20 How distressed are
you to receive this
lingerie?
88.66 308.198 .478 .826
21 How distressed are
you to eat this apple
from the cemetery?
89.29 308.246 .496 .826
22 How distressed are
you to use this charcoal
made of cremated
ashes?
87.80 309.477 .452 .827
23 How distressed are
you to throw the darts
at the baby?
88.50 309.519 .445 .827
24 How distressed are
you to rip off the head
of your close relative?
88.53 350.754 -.286 .858
25 How distressed are
you that the doll that
resembles you got run
over by a truck?
89.14 315.263 .365 .830

26 How distressed are
you to see your family
gazing at you while you
engage in an
embarrassing sexual
activity?
88.69 360.404 -.412 .862
27 How pleased would
you be choosing the
name of someone
famous?
88.74 319.611 .279 .832
28 How distressed are
you to use the floss that
looks like pubic hair?
87.96 303.254 .587 .823
29 How distressed are
you to use the vomit
colored toothpaste?
88.40 303.205 .574 .823
30 How distressed are
you to eat the cotton
candy shaped like a
tampon?
88.45 304.697 .529 .824
31 How distressed are
you to drink out of the
catheter?
88.36 300.651 .626 .821
This shows that if the variable number 26 is removed the cronbach alpha will increase to 0.86
which is higher than the existing value.
Now, the new cronbach alpha after removing the varialble is shown in the table below:
Reliability Statistics
Cronbach's
Alpha
N of Items
.862 30

The process was again followed and the analysis show that if the variable number 24 is removed
the cronbach will increase to 0.883.
In the next round variable number 24 is removed and the new value of cronbach alpha is as
follows:
Reliability Statistics
Cronbach's
Alpha
N of Items
.883 29
Similary, if the variable number 17 is removed then the value of cron bach value will increase to
0.889. The result after removing this variable is shown in the table below:
Reliability Statistics
Cronbach's
Alpha
N of Items
.898 28
After this round, even if the variables are removed from the analysis the value of cronbach apha
will not increase more than 0.898. So there is no need to remove more variables from the
analysis.
So, the value of cronbach alpha is highest when variable number 17, 24 and 26 are removed from
the analysis.
However, the entire analysis should not be analyzed on the basis of the cronbach alpha. In some
cases, the variable may not be contributing to the internal consistency, however it might be
important variable for the overall analysis of the research(Mitchell, 1996; Drost, 2011). So, all
the variables should be included in the analysis, after achieving a minimum level of cronbach
alpha. The more the number of variables, results from other analysis can be robust. So, achieving
the highest cronbach alpha should not be the only criteria for the selection of the variables
(Cronbach and Gleser, 1957; Shukla and Kumar, 2012).
References

Cronbach, L. J. and Gleser, G. C. (1957) Psychological tests and personnel decisions. Urbana:
University of Illinois Press.
Drost, E. A. (2011) ‘Validity and Reliability in Social Science Research’, Education Research
and Perspectives, 38(1), pp. 105–124.
Mitchell, V. (1996) ‘Assessing the reliability and validity of questionnaires: an empirical
example’, Journal of Applied Management Studies, 5(2), pp. 199–207.
Shukla, G. and Kumar, V. (2012) ‘Different Methods Of Analyzing Multiple Samples Repeated
Measures Data’, Journal of Reliability and Statistical Studies, 5(1), pp. 83–93.