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2.5.2 reliability

If test validity is defined as accuracy of measurement, test reliability is related to consistency of measurement. A reliable test score will be consistent across different characteristics of the testing situation. Unless test scores are relatively consistent, they cannot give any information at all about the ability measured. Another aspect of overall test reliability is rater reliability. Raters must maintain consistency in their own marking standards. This kind of reliability is called intra-marker reliability (Underhill, 1987). Or the same work marked by different raters should produce similar results, which is named inter-marker also by Underhill. If some raters rate more severely than others, the ratings of different raters are not consistent, and the scores obtained could not be considered to be reliable. Oral tests belong to the kind calling for subjective judgement on the part of the marker, so the scores awarded in an oral test cannot be believed to always have such high reliability.

It is also necessary to recognize that inconsistencies cannot be eliminated entirely. Nevertheless, it is possible to minimize the effects of the potential sources of inconsistencies under control in test design (Bachman and Palmer, 1996). Amongst factors affecting test performance, the characteristics of the test tasks are partly under control. In language test design and development, thus, it is possible to minimize variations in the test task characteristics that do not correspond to variations in target language tasks.

Test administration also involved in the concept of reliability has not been given proper attention at some universities at the present time. Administrating a test involves exam invigilators and such test conditions as classrooms, equipment, materials, exam rules and procedures dealing with test takers’ cheating.

2.5.3 practicality

Test practicality pertains to ‘the ways in which a test will be implemented, and, to a large degree, whether it will be developed and used at all’ (Bachman&Palmer, 1996, p. 35). It concerns practical matters such as the amount of time, human and material resources available for constructing a test, administering it, marking it, and interpreting the results. If the test resources required for implementing a test exceed the resources available, the test will be impractical. Human resources are a crucial component of test construction and administration involving such individuals as test writers, scorers or raters, and test administrators as well as clerical and technical support personnel. In fact, not all institutions have sufficient staff to be in charge of all these well-defined roles. One person may be in charge of several functions. Test writers, key personnel in the process of test development, are involved not only in writing tests but also in collecting materials, editing and recording. Material resources include space (the number of classrooms, language labs needed), equipment (typewriters, computers, cassette players, overhead projectors), test materials (test booklets, answer sheets, audiotapes). Time consists of test development time and the time required to complete the parts of each stage of the test development process.

Questions & Answers

Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
research.net
kanaga
sciencedirect big data base
Ernesto
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
Daniel
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
Maciej
characteristics of micro business
Abigail
for teaching engĺish at school how nano technology help us
Anassong
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
NANO
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
s.
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
Tarell
what is the actual application of fullerenes nowadays?
Damian
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
Tarell
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
Virgil
is Bucky paper clear?
CYNTHIA
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
NANO
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Harper
Do you know which machine is used to that process?
s.
how to fabricate graphene ink ?
SUYASH Reply
for screen printed electrodes ?
SUYASH
What is lattice structure?
s. Reply
of graphene you mean?
Ebrahim
or in general
Ebrahim
in general
s.
Graphene has a hexagonal structure
tahir
On having this app for quite a bit time, Haven't realised there's a chat room in it.
Cied
what is biological synthesis of nanoparticles
Sanket Reply
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Source:  OpenStax, Collection. OpenStax CNX. Dec 22, 2010 Download for free at http://cnx.org/content/col11259/1.7
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