Measurement and Assessment of Research Results

Four Levels or Scales of Measurement

Nominal Ordinal Interval Ratio

Four Levels or Scales of Measurement

Nominal – A, B, C, or 1, 2, 3 EX: 1 = boys, 2 = girls; 1 = in sports, 2 = not in sports; 1 = reduced lunch, 2 = not reduced lunch 1 = freshmen, 2 = sophomores, 3 = juniors, 4 =

seniors 1 = American, 2 = Canadian, 3 = Mexican 1 = experimental group, 2 = control group

Four Levels or Scales of Measurement

Ordinal – Rank from first to last, best to worst. Items are ranked, but the distance between them is unknown and variable.

EX: 1st in class, 2nd in class, 3rd in class 1st place in race, 2nd place, 3rd place No. #1 song, #2 song, #3 song Valedictorian, Salutatorian

Four Levels or Scales of Measurement

Interval – Rank with equal intervals or distance between numbers; lacks an absolute-zero point

EX: A students, B students, C students, D students Fahrenheit, Celsius, IQ,

Four Levels or Scales of Measurement

Ratio – Has all the properties of nominal, ordinal, interval scales plus an absolute-zero point EX: A test where someone could miss all

answers (number of right answers could equal zero)

Annual income, height, weight, response time

Other terms

Testing and assessment Testing – measuring variables with a device Assessment – gathering and integrating data –

tests, interviews, observations – to make an evaluation

Traits and States Traits – long-term characteristics

Free-floating anxiety States – short-term characteristics

Situational anxiety

Identifying a good test or assessment procedure - Reliability and Validity

Reliability – if the student takes the same test multiple times, does he get nearly identical scores Test + retest has pollutants. Familiarity with the

test if the time is too short, growth of the individual if the time is too long

Identifying a good test or assessment procedure - Reliability and Validity

Split-Half Reliability – split the test in twoEx: odd questions vs even

questions, first 25 questions vs next 25 questions

Identifying a good test or assessment procedure - Reliability and Validity

Validity – Does the test support the actions we take based on the scores

Does it test for the traits we were researching? Gathering evidence supporting the score inference

EX: IQ of 130 assures success in college; if many show IQ of 130, but fail college, test may lack validity

EX: High scores on algebra aptitude test imply success in algebra class; use validity coefficient or expectancy data to determine. Kids fail algebra, problem with test

Achievement vs Aptitude tests

Achievement tests measure degree of learning after a person has been exposed to a specific learning experience

Aptitude tests measure broader learning based on information acquired through a lifetime of learning

Additional examples of Expectancy Data = Aptitude Tests

SAT for college bound imply they will succeed

CSAT for teachers imply they will succeed LSAT for law students imply they will

succeed MCAT for medical students imply they wil

succeed