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Test and measurement
Chapter 4 and 5
Question | Answer |
---|---|
Psychology owes the advanced development of reliability assessment to the early work of | Charles Spearman |
Abraham introduced the notion of | sampling error |
The term error refers to discrepancies that will always exist between....... ability and the ...... of ability | true, measurement |
the difference between a persons true score and observed score results from | measurement error |
the equation for true/observed score | X = T + E |
Spearman published the earliest work on reliability theory in his 1904 article | "The proof and measurement of Association between two things" |
The distribution of random errors is what shape | bell shaped |
Dispersion around the observed scored tells us | how much error there is in the measurement |
Classical teat tehory uses the standard deviation of this distribution as a basic measure of error called | the standard error of measurement |
standard error of measurement tells us | on average, how much an observed score deviates from a true score |
if three random samples of items are selected from the entire domain of all possible items, each of the three samples should yield an unbiased estimate of the ........ related to the domain | true score |
Reliability coeffiecients are | ratio coefficients that can also be expressed as the ratio of the variance of the true score on a test to the variance of the observed score on a test |
reliability coefficients cab be interpreted as the proportion of variation in observed scores that can be attributed to | actual differences among people |
three methods of estimating test reliability | test-retest, parallel form, and internal consistency |
test-retest | consideres the consistecy of the test results when the test is admistered on differen occasions |
parallel forms | evaluate the test across differen froms of the test |
internal consistency | we examine how people perform on similar subsets of items selected from the same form of the measure |
Test-Retest is appropritate when | it is assumed a trait being measured does not change over time... E.G intelligence |
Carryover effect | occur when something about taking the test the firsttime influences the second time the test is taken |
carryover effect can lead to an.......... of the true reliability of a test | overestimate |
Parallel forms | the correlation between form a and from b of a test |
split half method | a test given and divided into halves that are scored separately |
Split half method can measure | internal consistency |
Problem with split half | how its split; one half may have more difficult problems than the other half |
to correct for half lenght you can use the.... formula | spearman-brown formula |
spearman brown formula allows you | to estimate what the correlatoin between the two halves would have been if each half had been the length of the who test |
spearman brown formula | R= 2r/(1+r) where r is the correlation between the two halves |
the spearman brown formula increases the | reliability |
Coefficient alpha | estimates teh internal consistency of tests in which the items are not scored 0 to 1 (right or wrong) in doing so he developed a more general reliability estimate |
under what cirumstance is coefficient alpha appropriate measure of internal consisteny reliability of a test | when items are not dichotomosly scored |
all measures of internal consistency (split half, coefficient alpha) evaluate the extent to which the different items on a test | measure the same ability of trait |
if a test is designed to measure several different traits or characteristics, .................., is a good way to examine whether items within subgroups or components are internally consistent | factor analysis |
behavirol psychologist prefer to use | observation of behavior opposed to psychological test |
To asses the behavioral observations we must asses the reliability of the observer: two ways | interrater reliability or kappa |
interrater reliability | the consistency among different judges who are evaluating the same behavior |
three ways to an observer can evaluate behavior | record the precentage of times that two or more observers agree, kappa statistics |
kappa statistics was introduced by | J. Cohen in 1960 |
Kappa statistics is | an agreement between two judges who each rate a set of objects using nominal scales. |
the standard error of measurement is used to form .........around observed scores. Th | confidence intervals |
Confidence intervals allow us to estimate the probability that the ........... falss within certain interval | true score |
the interval around the observed score is the | confidence interval |
if we have an 82 observed score and a 95% CI this means that | we are 95% that the true score relies around 78-84 interval |
when importnat decisions are to be made on the basis of test socre, reliability coefficients should be ...... or higher | .95 |
basic research should have a reliability coefficient of | .70 to .80 |
allows test developers to estimate what the correlation between two measures would have been if the they had not been measured with error | correction for attenuation |
a reliability of a difference score is expected to be | lowere that the reliability of either test on which it is based |
administering two supposedly equivealent forms of test (form a and form b) to the same group of individuals yilelds a correlation coefficient indicating | alternative forms reliability |
what did the suprem court rule in the case of Griggs vs. Duke Power? | Employees must provide evidence that a test used for selection of promotion of employees has a specific meaning. |
Validity is | the agreement between test score or measure and the quality it is believed to mesure. "Does the test measure what is supposed to?" |
Three primary types of evidence that can suppor a tests validity | face validity, content, and criterion related validity, |
Face validity | mere appearance that a mesure has validity. If the items seem to be reasonably related to the perceived purpose of the test. |
Face validity is not really validity because | it does not offer evidence to support conclusions drawn from test scores |
consideres the adequacy of representation of the coneptual domain the test is designed to cover | content-related validity |
has the test been constructed adequately would be what type of validity | content |
contruct under representation is | the failure to capture important components of a construct |
If a math test on included algebra not geometry this would be an example of | consrtuct under representation |
Construct irrelevant variance is | when scores are influenced by irralevent factors |
Test Anxiety, illiness, sleepy, are all factors that might influence a test this is temred | construct irrelevant variance |
Criterion Related Evidence for Validity | tells us how well a test corresponds with a particulare criterion. Provided by high correlations between a rest and a well-defined criterion measure |
predicitve validity | the forecasting function of test |
Concurrent Relate evidence for validity is | assessments of thei simultaneous relationships between the test ad the crieterion-- such as between a learning disability and school performance |
Validity coefficient | relationship between a test and a criterion is usually expressed a correlation called Validity coefficient |
Are scale correlates well with other scales is an example of what type of evidence | Concurrent evidince (under criterion) |
Construct validity evidence | is established through a series of activities in the which a reseracher simultaneously defines some construct and develops the instrumentation to measure it. |
A construct is | something built by mental synthesis. Ex. Intelligence, love, curiosity, or mental health |
convergent evidence | - When a measure correlates well with other tests believed to measure the same construct |
- Convergent evidence is obtained in one of two ways | - 1) we show that a test measures the same things as other tests used for the same purpose. |