Exercise 4
1. Based on the information provided from the Dingley and Roux (2014) study, which
scale has the lowest reliability or Cronbach's alpha coefficient? What random error did
this scale have for this study? Was this a study strength or weakness?
The Inner Strength Questionnaire (ISQ) is the scale with the lowest reliability, with a
Cronbach's alpha coefficient in 0.89 in the sample.
The random error is: 1.00- (0.89 X 0.89) = 1.00- 0.7921= 0.2079.
This study is strength, highly reliable, due to all the three variables have Cronbach’s alpha
coefficient greater than 0.80.
2. Would you consider the Center for Epidemiological Studies Depression Scale (CES-
D) a reliable measure of depression for this population of women with cancer? Provide
a rationale for your answer.
Yes, I consider the CES-D a reliable measure due to:
- Cronbach's alpha in this study was 0.90
, -CES-D is one of the most widely used self- report instruments for epidemiologic studies of
depression, being used in primary care, psychiatric and related clinical and forensic settings,
this shows that subjects are able to read and understand the items on the instrument in order
to complete it consistently and accurately (appropriate reading levels or readability score for
their measurement methods)
- The 20 item instrument measures depressive affect, somatic symptoms, positive affect, and
interpersonal relations. For each experience related to depression, the respondent selects the
value that best describes how frequently the experience occurred during the previous week. If
the subject complete the scale in a similar way from one time to the next, this indicate test-
retest reliability.
3. What type of reliability testing is presented for the three scales in the Dingley and
Roux
(2014) study? Provide a rationale for your answer.
1. Based on the information provided from the Dingley and Roux (2014) study, which
scale has the lowest reliability or Cronbach's alpha coefficient? What random error did
this scale have for this study? Was this a study strength or weakness?
The Inner Strength Questionnaire (ISQ) is the scale with the lowest reliability, with a
Cronbach's alpha coefficient in 0.89 in the sample.
The random error is: 1.00- (0.89 X 0.89) = 1.00- 0.7921= 0.2079.
This study is strength, highly reliable, due to all the three variables have Cronbach’s alpha
coefficient greater than 0.80.
2. Would you consider the Center for Epidemiological Studies Depression Scale (CES-
D) a reliable measure of depression for this population of women with cancer? Provide
a rationale for your answer.
Yes, I consider the CES-D a reliable measure due to:
- Cronbach's alpha in this study was 0.90
, -CES-D is one of the most widely used self- report instruments for epidemiologic studies of
depression, being used in primary care, psychiatric and related clinical and forensic settings,
this shows that subjects are able to read and understand the items on the instrument in order
to complete it consistently and accurately (appropriate reading levels or readability score for
their measurement methods)
- The 20 item instrument measures depressive affect, somatic symptoms, positive affect, and
interpersonal relations. For each experience related to depression, the respondent selects the
value that best describes how frequently the experience occurred during the previous week. If
the subject complete the scale in a similar way from one time to the next, this indicate test-
retest reliability.
3. What type of reliability testing is presented for the three scales in the Dingley and
Roux
(2014) study? Provide a rationale for your answer.
