PSYC 201W Lecture Notes - Lecture 5: Cronbach'S Alpha, Level Of Measurement, Face Validity

• School: Simon Fraser University
• Department: Psychology
• Course: PSYC 201W
• Professor: Russell Day

Document Summary

Variables - condition or characteristic can take on different values or categories. Measurement - assignment or symbols or numbers to something according to a set of rules. Scales of measurement: nominal scale - symbols to name, classify or categorize, ordinal scale - rank order scale of objects or individuals, equal distances on scale not necessary equal on dimension being measured. Interval scale - equal distances between adjacent numbers: ratio scale - highest scale of measurement (preferred method), same properties of other scales plus absolute zero point (ie. reaction time, length, etc. ) Reliability - refers to consistency or stability of the scores on your measurement instrument. Validity - refers to the extent to which your measurement procedure is measuring what you think it is measuring and whether you have interpreted your score correctly. *note: a measure with no reliability necessarily has no validity!