Chapter 5_Reliability and Validity.ppt

Chapter 5_Reliability and Validity.ppt - Reliability and...

Info iconThis preview shows pages 1–5. Sign up to view the full content.

View Full Document Right Arrow Icon
Reliability and Validity
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Reliability and validity Evaluating the relationship between measured and conceptual variables How do we know whether the measures assess the conceptual variable Distinguishing between the conceptual variable of interest and other influences (error) Random – chance fluctuation in measurement Systematic - systematic increase or decrease the score on the measured variable
Background image of page 2
Random and systematic error Self-control Likert Scale (Tangney et al., 2004) Influence of the conceptual variable Random error (coding errors, time of measurement, question misunderstanding Threats to reliability Systematic error (Other conceptual variables: poor executive functioning) Threats to validity
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Reliability The extent to which the measure is free from random error Actual score = True score + Random Error Test-retest reliability Stable traits and aptitudes Retesting effects Equivalent forms Internal consistency The scores on the items correlate with each other Split-half Cronbach’s coefficient alpha (reflects the underlying correlational structure of the scale) Item to total correlation (in the development phase) Interrater reliability Reliability = True Score Actual Score
Background image of page 4
Image of page 5
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 02/26/2011 for the course PSYC 420 taught by Professor Staff during the Fall '08 term at Maryland.

Page1 / 12

Chapter 5_Reliability and Validity.ppt - Reliability and...

This preview shows document pages 1 - 5. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online