Accuracy and reliability
(Cronbach’s alpha)
Estimating the reliability of a scale is based on the correlations between the measurements or items of the scale that make up the scale in relation to the variance of the items. Each measurement consists of a true result for a given concept or phrase, but also an unknown random error. The more a measurement reflects mostly the true result, the more reliable it is. Therefore, the final result is influenced by the number of concepts or phrases – a larger number of scale elements used makes it ultimately more reliable (measures a given phenomenon more accurately).
This is an important reservation from the point of view of the number of features and the number of expressions proposed in the developed psychometric tests. Well, each feature consists of 6 phrases that measure the candidate’s competence in a given area. It’s not much at all. At the same time, the level of final matching to a given job is measured not by one feature, but by 5-7 features, so ultimately it is a scale of 30-42 phrases.
Cronbach’s alpha coefficient was used in the reliability analysis of the developed scales:
where s2i is the variance of k individual items, s2sum is the variance of the sum of all items. The formula shows that if the expressions do not give a true result, but only an error, then the variance of the sum will be the same as the sum of the variances of the individual expressions – then α = 0. In a situation where the error is negligible and the results are true, α tends to the value 1.
In other words, in the interpretation of the result, the closer the value of Cronbach’s alpha is to 1 (for social measurements we assume 0.9), the more reliable the given scale is. However, it is assumed that above 0.6 the potential unknown error is no longer significant.
Results of the Cronbach’s
alpha coefficient
PERSONALITY TRAIT | RELIABILITY (CRONBACH’S ALPHA) | CONDITION OF ONE-DIMENSIONALITY |
---|---|---|
Assertiveness
|
0,73
|
fulfilled
|
Building a relationship
|
0,76
|
fulfilled
|
Patience
|
0,72
|
fulfilled
|
Decision
|
0,87
|
fulfilled
|
Flexibility and compliance
|
0,75
|
fulfilled
|
Readiness for individual work
|
0,83
|
fulfilled
|
Ready to work in various environmental conditions
|
0,81
|
fulfilled
|
Ready for a fast pace of work
|
0,79
|
fulfilled
|
Own initiative
|
0,76
|
fulfilled
|
Quality of work
|
0,70
|
fulfilled
|
Communicativeness
|
0,79
|
fulfilled
|
Attention focus
|
0,86
|
fulfilled
|
Consistency
|
0,76
|
fulfilled
|
Emotional control
|
0,90
|
fulfilled
|
Creativity
|
0,77
|
fulfilled
|
Personal culture
|
0,71
|
fulfilled
|
Establishing contacts
|
0,80
|
fulfilled
|
Resistance to stress
|
0,79
|
fulfilled
|
Responsibility
|
0,71
|
fulfilled
|
Organization of work
|
0,81
|
fulfilled
|
Persuasion and negotiations
|
0,69
|
fulfilled
|
Routine work
|
0,73
|
fulfilled
|
Compliance with standards and rules
|
0,70
|
fulfilled
|
Solving problems and conflict
|
0,74
|
fulfilled
|
Reliability and accuracy
|
0,80
|
fulfilled
|
Independence
|
0,84
|
fulfilled
|
Self-control
|
0,82
|
fulfilled
|
Self-motivation
|
0,78
|
fulfilled
|
Systematicity
|
0,84
|
fulfilled
|
Sensitivity and empathy
|
0,75
|
fulfilled
|
Cooperation
|
0,82
|
fulfilled
|