MGTO 324

Workshop 4: Reliability

Activity 1

Use the data management concepts discussed in the last lesson to input all the data provided on the given sheets.

This is a General Self-efficacy scale (a Chinese Version) and the data are real.

SPSS: Assessing reliability

Split-half reliability

SPSS: Assessing reliability

Split-half reliability

SPSS: Assessing reliability

Split-half reliability

Reliability Statistics

.9082a

-.016b

2c

4.629.772.772

.769

ValueN of Items

Part 1

ValueN of Items

Part 2

Total N of Items

Cronbach's Alpha

Correlation Between FormsEqual LengthUnequal Length

Spearman-Brown Coefficient

Guttman Split-Half Coefficient

The items are: var00005, var00006.a. The value is negative due to a negative average covariance among items. This violatesreliability model assumptions. You may want to check item codings.

b.

The items are: var00007, var00008.c.

Activity 2

1. Calculate the Split-half reliability of your data

Correlation = ?

Spearman-Brown coefficient = ?

2. Interpret your findings

SPSS: Assessing reliability

Cronbach’s Alpha

SPSS: Assessing reliability

Cronbach’s Alpha

Reliability Statistics

.717 4

Cronbach'sAlpha N of Items

Activity 3

1. Calculate the Cronbach’s alpha of your data

2. Interpret your findings

SPSS: Item screening

Cronbach’s Alpha

Inter-Item Correlation Matrix

1.000 .884 .926 .002.884 1.000 .885 -.026.926 .885 1.000 -.008.002 -.026 -.008 1.000

var00005var00006var00007var00008

var00005 var00006 var00007 var00008

The covariance matrix is calculated and used in the analysis.

SPSS: Item screening

Cronbach’s Alpha

SPSS: Item screening

Cronbach’s Alpha

Item-Total Statistics

25.5273 4.551 .823 .52624.6890 3.697 .746 .49025.3840 3.544 .778 .46325.0957 6.358 -.012 .950

var00005var00006var00007var00008

Scale Mean ifItem Deleted

Scale Varianceif Item Deleted

CorrectedItem-TotalCorrelation

Cronbach'sAlpha if

Item Deleted

Activity 4

1. Run the screening item procedure

2. Any items you think we have to delete in order to increase the reliability of the test?

Assignment

1. Complete Activities 1 to 4. Please include the relevant SPSS outputs.

2. Submit the hardcopy to me with less than TWO A4 pages.