Potential hinder mechanisms to assessment

Some thoughts drawn from realism:

1. maybe teachers can't employ their assessment methods because it is not legitimate (i.e., by the ministry of education, by the pedagogical institure, by discipline counsellor etc.). Or maybe they don't have the available resources (i.e., time, especially if the curriculum is very pressing, or it is only an one-hour per week course) to employ other assessment methods (e.g., it's convenient and time efficient to employ only one test per semester and grade students from that test). (accessibility mechanism?)
2. maybe teachers don't have enough information about assessment methods and they just use "traditional" assessment models (information mechanism). 'Even tutors who are interested in pursuing other goals may lack knowledge of the most appropriate strategies to use and sill in carrying out different kinds of teaching roles. Although they have different aspirations, they are limited to reproducing the model of teaching that they experienced as students' (Toohey, 1999, 67)
   
3. maybe teachers view assessment as a burden (e.g. they are over-stressed from parents-students) and subsequently dont recognise its pedagogic value (a needs and expectation mechanism?)
4. some courses are less significant than others, for example there are no final exams for ICT and music in secondary schools, some courses in high schools are optional and the overall grade is not affected by the grade in the optional courses. Does this affect assessment methods? (a needs and expectation mechanism?)
5. assessment is affected by school context: the curriculum is delivered via interaction in the classroom where there are expectations and rules about the behaviour of both teachers and pupils, which may or may not vary from class to class, teacher to teacher, school to school, etc. (p.39). 
6. Mechanisms can run on various levels: micro and macro, group, organizational, etc. (for more details look at p.38-39).

Which mechanisms of the above appear to be the "bankers" (i.e., those agreed to be the ones to concentrate on)? To what grade the above mechanisms affect my topic?


The desirable end-state of my research should be to come up with one or more postulate mechanisms which are capable of explaining the phenomena; that I have good reason to believe in their existence; and that I can specify the contexts in which these mechanisms operate to produce and outcome/effect or in reverse to block the outcome/effect. (p.38)
While we are seeking potential causal explanations which were in operation we should eliminate alternatives which might have been involved (p.40).

references:
Real World Research: A Resource for Social Scientists and Practitioner-Researchers, 2nd Edition. Colin Robson. (p.37-40)