|Course:||Postgraduate Certificate - Tertiary Level Teaching|
|Module:||Assessing Student Performance|
|Page:||3 - Desirable characteristics of student assessment procedures|
Desirable characteristics of student assessment procedures
Let us begin by identifying the basic features that should characterise a 'good' student assessment procedure. Such a procedure should, ideally, be valid, reliable, practicable, fair and useful to students.
A valid assessment procedure is one which actually tests what it sets out to test, ie one which accurately measures the behaviour described by the learning outcomes under scrutiny. Obviously, no one would deliberately construct an assessment item to test trivia or irrelevant material, but it is surprising just how often non-valid test items are in fact used - eg questions that are intended merely to test recall of factual material but which actually test the candidate's powers of reasoning, or questions which assume a level of pre-knowledge that the candidates do not possess.
As we will see later in the review of assessment methods, validity-related problems are a common weakness of many of the more widely-used methods. For example, a simple science question given to 14-year-old schoolchildren ('Name the products of the combustion of carbon in an adequate supply of oxygen') produced a much higher number of correct answers when the word 'combustion' was replaced by 'burning'. The original question had problems of validity in that it was, to some extent, testing language and vocabulary skills rather than the basic science involved.
The reliability of an assessment procedure is a measure of the consistency with which the question, test or examination produces the same results under different but comparable conditions. A reliable assessment item gives reproducible scores with similar populations of students, and is therefore as independent of the characteristics and vagaries of individual markers as possible. This is often difficult to achieve in practice.
It is obviously important to have reasonably reliable assessment procedures when a large number of individual markers assess the same question (eg in national school examinations, or with many postgraduates marking lab work). A student answer which receives a score of 75 per cent from one marker and 35 per cent from another, for example, reveals a patently unreliable assessment procedure.
To help produce reliability, the questions which comprise an assessment should (ideally) test only one thing at a time and give the candidates no choice. The assessment should also adequately reflect the desired outcomes of the teaching unit. Note that the reliability and validity factors in an assessment are in no way directly linked - a test or examination, for example, may be totally reliable and yet have very low validity, and vice versa.
For most purposes, assessment procedures should be realistically practical in terms of their cost, time taken, and ease of application. For example, with a large class of technicians being trained in electrical circuitry, it may be convenient to use only a paper-and-pencil test rather than set up numerous practical testing situations. Note, however,that such compromises can reduce the validity of the assessment.
With the spread of competence-based courses, and the need to carry out increasingly complicated continuous assessment in order to assess the attainment of the various competences that such courses are designed to develop, problems of practicability have assumed ever-increasing importance. These problems are compounded by the requirement that students undertaking such courses be allowed several attempts to demonstrate that they have reached an acceptable standard in a particular competence.
With increasing student numbers and a continuing decline in the unit of resource, intolerable strain can be put on lecturers, particularly where assessment of competence or double marking of assessments is involved. Some people suggest that students' work receives less careful attention or annotation than in the past. As a consequence, new and practicable alternatives to marking by lecturers are emerging. Lecturers are increasingly likely to devolve marking - to postgraduate tutors, to applications/technical staff, to computerised systems. The lecturer's responsibility for ensuring validity, reliability, fairness and feedback remains.
To be fair to all students, an assessment must accurately reflect the range of expected behaviours as described by the published course outcomes. It is also highly desirable that students should know exactly how they are to be assessed. Indeed, it is now generally accepted that students have a right to information such as the nature of the materials on which they are to be tested (ie content and outcomes), the form and structure of the test or examination, the length of the examination, and the value (in terms of marks) of each component of the course. With the spread of Student Charters and the increasing tendency for students (especially those responsible for paying their own fees) to demand 'value for money', the need for assessment to be manifestly fair becomes even more important.
Usefulness to students
Students should also find assessment useful, in that it contributes to the effectiveness of their learning. It should do this in two different ways, namely, by getting them to carry out tasks that facilitate learning (revising material covered in lectures, writing essays, etc) and in providing them with feedback on how they are progressing, thus helping them to identify their strengths and weaknesses.
Continuous assessment has obvious advantages over terminal assessment in both these regards, but even this is only of real value to students if they are provided with detailed feedback on their work without undue delay. Performance standards increasingly specify turnaround time. Additionally, it is obvious that all work should actually be returned to the students (albeit on a temporary basis, in some cases) after being marked - something that does not always happen.