Question

A scale can be reliable and yet not valid. Provide an example of such a scale that is different than the one found in the text. Remember that a scale means a type of measure such as personality inventory, a skills inventory, a norming chart. DO NOT PROVIDE AN EXAMPLE OF A SCALE THAT WEIGHS SOMETHING (can you tell that many students have done that in the past?).

Include in your answer why you selected or created this particular example.

Answer 1

Test reliability and validity are the two technical properties of the test that indicate the quality and usefulness of the test . THese two most important characterstics of the test . we may examine these features when evaluating the suitablity of the test for our use .

The reliability refers to how dependly or consistently a test measures a characterstics . If a person takes the test again , will he or she get a similar test score or amuch diferent score . A test that yeild the scores for a person who repeats the test is said to measure a characteristic reliably.

sometime the account of individual who does not get exactly the same test score every time he or she takes , some possible reason might be this-

for example ;-test performance can be influenced by a person's psychological or physical state at the time of testing or motivation may affect the applicant's teat results.

environment factors ;- differences in the testing environment , such as room temperature , lightening , noise , even the test administrator , can influence an individual's test performance

Test form;- many test have more than one version or form . items differ on each form , but each form is supposed to measure the same thing , different forms of a test are known as parallel forms or the alternate forms . Thses forms are designed to have yhe similar measurement characterstics , but theyy contain different items . Because the forms are not exactly the same , a testtaker might do better on one form than on another ,

Multiple raters;- In certain test, scoring is determined by a rater's judgement of the test taker's performance or responses . difference in training , experence , and the frame of reference among raters can produce differnetscores for the test taker .

EXAMPLE - an individual 's reading ability is more stable over a particular period of time , than that individual's anxiety level . Therefore we would expect a higher test retest reliabilty coefficient on a reading test than we would on a test that measures anxiety . for contruct that are expected to vary over time , an acceptable test retest reliability coefficient may be lower than is suggested.

Validity is the most important issue in selecting a test , A validity refers to characterstics the test measures and how well the test measures that characterstics ;Validity tells us if the charcterstics being measured by a test is related to job qualifications and requirement ,The validity gives meaning to the test scores , The validity evidence indicates that there is linkage betwwen test performance and job performance , It can tell that what we may conclude or predict about someone from his or her score on the test , If a test has been demobstrated t be a valid predictor of performannce on a specific job . we can conclude that person scoring high on the job than person who score low on the test , all else being equal .Validity also describes the degree to which we can make specific conclusion or prediction about people based on their test scores , In other words it indicates the usefulnessof the test.

For example ;- Employee 's scores ( predictor) on a test designed to measure mechanical skill could be coorelated with their performance in servicing machines ( criterion) in the mill , IF the correlation is high , it can be said that the test has a high degree of validation support and its use as a selection tol would be appropriate .

This example is best to be choose because it s related to the mental health , as we know that mental health is equally imporatnt as it is physical health , we genearlly talked about on physical health then why we left over our mental health it could be better to take it with hand on hand with physical health,