BS ISO IEC 33003:2015 pdf free download – Information technology – Process assessment – Requirements for processmeasurement frameworks
4.2.2Guidance
Although a process quality characteristic or process attribute should convey an intuitive understandingof what it represents, interpretation may vary according to the observer. Thus, a definition is requiredto explain and provide the meaning of a construct. This is called the construct definition.
Clarification of a construct implies that for example the definition of the process quality characteristicas specified super-ordinate fully covers all of process attributes on the basis of construct specification,where process attributes as sub-ordinates are its distinct dimensions.A latent variable can be assigned to aunidimensional construct in the model.Statistical methods related to dimensionality are introduced in C.1.
4.3.2Guidance
When a process attribute is directly observable through formal assessments, self-reports,surveys(including questionnaires and interviews), observations, or other empirical means, it is a base measurethat is functionally independent of other measures. If a process attribute is measured with its severalsub-constructs or measures, it can be considered as a construct.Four or more base measures arerecommended to measure a construct and perform a set of statistical tests (including model validationand construct specifications) in reflective specification.
NOTE Refer to Clause 6.3.4 of ISO/IEC 33004 for assessment indicators that are utilized for processattribute rating.
4.4.2Guidance
There are two kinds of construct specifications that refer to the way in which the latent variablerepresenting the construct is linked to its measures (i.e., the relationship between a unidimensionalconstruct and its measures): reflective and formative measurement models. A process qualitycharacteristic or process attribute can be viewed either as underlying factors or indices produced byobserved measures.The former is referred to as reflective(effect) constructs or reflective measurementmodels, and the latter formative (causal) constructs or formative measurement models.
The objective of a reflective measurement model is to measure a single property by using multiplemeasures,whereas a formative model attempts to summarize multiple properties with a single composite value.In Annex B, these two specifications can be represented as Figure B.1 (a) and Figure B.1(b), respectively.
Decision rules to examine reflective or formative, construct specification, are summarized in Table 1.These decision rules can be applied to the process quality characteristic and its associated processattributes. They can be assessed a priori statistical validation of construct specification.Annex Bprovides the construct specification in detail.
In some instances, the relationships depicted in Figure B.1 (Annex B) can have a higher-order level,i.e., conceptual definitions of constructs are often specified at a more abstract level, which sometimesinclude multiple reflective and/or formative first-order dimensions. The definition of a higher-ordermodel should be theory-driven in a reflective measure model. Statistical analyses should be used tosupport or validate the definition.
4.5.2Guidance
Some assessments can generate the ratings of for example a process quality characteristic or processattributes for individual process instances assessed.On the other hand, others providing an overallpicture without ratings can simultaneously assess a set of process instances under the same context as aprocess.Ratingofprocess attributes can be based on formalassessments,self-reports,surveys(includingquestionnaires and interviews), observations,or other empirical means.Thus, a measurement scale forrating base measures should be consistent with the granularity of assessment. Occasionally, rating inself-reports or surveys is on the base of perception rather than objective evidence. Rating scale for theprocess quality characteristic and its process attributes should be addressed with rationale, consistentwith the construct specification (refer to 4.3).