Chapter 4: Test administration

z scoresStandard score expressed in terms of

standard deviation units which indicates distance raw score is from mean.

z scores can be positive (score above mean) or negative (score below mean)*

A z score of 0 is the meanz= X-X or X-X *

s s * occurs when the better score is lower than

the mean (golf, time in a race, percentage of body fat)

Let’s try it:You have a set of scores for the long jump

and the mean is 50 with a standard deviation of 5. What would the z score of the score 42 be? How about 55?

How about this one: you have a set of golf scores with a mean of 10 and a standard deviation of 2. What would the z score of the score 12 be? How about 7?

T scoresDerived from a z scoreWill always be a positive whole number with a

T score of 50 representing the meanEasier for some to comprehend since it is on a

scale of 0-100T= 10z +50 or 10 (x-x) +50

sSo, can you calculate a T score from a -2.4 z

score? How about from a z score of +3.7?

z and T scoresz scores have a standard deviation of 1 with a

mean of 0T scores have a standard deviation of 10 with a

mean of 50So, a +1 z score = a T score of 60; a -2 z score = a

T score of 30Since we know that when scores are normally

distributed that 99.7% of all scores will fall between a standard deviation of +- 3, we rarely have a T score above 80 or below 20

We can also so that a score at the 84th percentile is equal to a z score of +1 and a T score of 60. Why?

CorrelationRelationship between two variablesCorrelation coefficient is the statistic that

indicates the relationship or association between variables

Correlation does not mean cause and effectYou could compare the relationship

between height and weight for a group of students (+ correlation)

You could compare speed in the 100 meters and long jump (inverse correlation)

Correlation CoefficientsWith a positive correlation the change of

direction of both variables will be the same (either both increase or decrease)

With an inverse correlation the change of direction of one variable increases as the other decreases

The degree of correlation or relationship is determined by a number from -1.00 to +1.00

The higher the number regardless of sign, the more closely related the variables

The lower the number regardless of sigh, the less closely related the variables

Rules to rememberCorrelation coefficients fall between +- 1.00The sign of a correlation coefficient indicates

type of relationship (positive or inverse)+- .80- 1.00= high relationship+- .60-.79 = Moderately high relationship+- .40-.59 = Moderate relationship+- .20- .39 = Low relationship+-0-.19 = no relationship

+.75 and -.75 indicate the same degree of relationship but one is positive and one is inverse

Correlational ProceduresPearson Product Moment Correlation…..requires interval or ratio dataSpearman Rho Rank Order Correlation…..requires ordinal data

Definition of TestTest – an instrument, protocol, or technique

used to measure a quality or quantity of properties or attributes of interest.

Can you give an example of a test from each domain?

Critical Test Criteria Test Objectivity – type of reliability related

to the administration of the testTest Reliability – consistent, repeatable

resultsTest Validity – accurately measures the

attribute that the test is designed to measure

Establishing ObjectivityTeacher must understand the test.Teacher must administer test appropriately

– follow protocols.Students must understand how test is

performed and how it is scored.There is no substitute for common sense in

measurement and evaluation!

Establishing ReliabilityTest – Retest ReliabilityAlternate Form ReliabilitySplit Half or Odd-Even Reliability

Which method is typically used in tests that require physical performance?

Establishing ValidityFace ValidityContent ValidityConstruct ValidityConcurrent ValidityPredictive ValidityWhich of these presents the strongest

rationale for validity?

Relationship of Validity, Reliability, and ObjectivityWithout objectivity, an instrument will lack

reliability.A test may be reliable but not valid.Without reliability, a test cannot be valid.

Therefore, objectivity is a prerequisite for reliability, and reliability is a prerequisite for validity.

Administrative Concerns in Test SelectionRelevanceEducational ValueEconomyTimeEnjoyment Availability of NormsDiscrimination

Administrative Concerns in Test Selection (continued)IndependenceGender AppropriatenessReliance on Another’s PerformanceSafetyTesting Large GroupsEase of Scoring, Interpreting, and Reporting

Planning Test AdministrationKnow the test.Prepare the test area.Train testers (assistants).Warm up for physical activity tests.Standardize instructions.Practice test items.Record scores efficiently.Interpret and evaluate the results.