Psych 325 1st Edition Lecture 7Part 2: An Introduction to Psychological Measurement-Measurement MattersoMeasurement-Systematic way of assigning numbers or names to objects and their attributesoWe need good measurement-Required to understand world-Need objective measures not just impressions of world-Need to measure DV's-Crucial to correlational studies because both cause and effect are measuredoBad measures=bad researchoHow do we do research?-If it exists, it can be measured.oMeasurement provides a bridge between theoretical concepts and empirical variables. -Could you imagine a recipe saying "add some of this"?-Chemists and physicists must measure chemicals and weights-If they couldn't do this, they would be in big trouble-Different types of measuresoVerbal-Verbal response-i.e. self-esteem scaleoBehavioral-Real behavior-i.e. avoiding someoneoBehavioroid-Participant reports on own behavior-i.e. condom useoPhysiological -Biological processes-i.e. brain imaging-Measuring Hidden VariablesoMuch of what psychologists measure can't be seenoTheoretical constructs-Theory says they exist-"Latent" or hidden variablesoIndicators-What we can observe-Result of theoretical constructsoOperationalization-Finding good indicators of theoretical constructsThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.Types of Measurement Scales-The properties of measurement scalesoAssess differences-Property of all scalesoMagnitude of attributes-Something greater or lesseroEqual intervals between magnitudes of attributes-Points are equivalentoTrue zero-Zero=none of attribute exists-Types of scalesoNominal: group membership-Assign names, numbers-Assess differencesoOrdinal: rank ordering-Assess differences and magnitude-Unit differences not meaningfuloInterval: rand and equal intervals-Unit differences are meaningful-Ratios don't make senseoRatio scale: interval with true 0-Ratios make sense-Nominal ScaleoGroups-Assign names, numbersoProperties-Assess differencesoExample-Demographic characteristicsoStatistics-Least information, but useful-Chi-square with nominal scales-T-tests, ANOVA with other scales-Ordinal ScaleoRank ordering on dimensionoProperties-Assess differences, magnitude of attributes-Intervals aren't equaloExample-Class rank-Year in schooloStatistics-Non-parametric statistics with ordinal scales-T-tests, ANOVA with other scales-Interval ScaleoOrdered with equal intervalsoProperties-Assess differences, magnitude of attributes, equal intervals-May have arbitrary zerooExample-IQ-AttitudesoStatistics-Can add or subtract number-All parametric statistics-Ratio scaleoInterval scale with true zerooProperties-Has all four principlesoExamples-Weight -TimeoStatistics-Ratios make sense-All parametric
View Full Document
Unlocking...