17352 05ppt
- 1. Introducing Communication Research 2e © 2014 SAGE Publications Chapter Five Measurement: Research Using Numbers
- 2. Key Concepts • NOIR – nominal ordinal interval ratio • Reliability • Validity • Scales • Numerals - labels such as zip codes • Numbers - can be computed Introducing Communication Research 2e © 2014 SAGE Publications
- 3. “N-O-I-R” Measures can be - • Nominal - labels • Ordinal - rank order • Interval - numeric scale • Ratio - numeric scale with a zero point. Introducing Communication Research 2e © 2014 SAGE Publications
- 4. “N-O-I-R” Examples • Nominal - press, radio, television • Ordinal - freshman, sophomore, junior • Interval - age (years): __ 0–4 __ 5–9 __ 10–14 • Ratio - age in years ____ Introducing Communication Research 2e © 2014 SAGE Publications
- 5. Validity & Reliability Measures must have – • Validity – ▫ measure what they are supposed to measure. and • Reliability – ▫ perform consistently. Introducing Communication Research 2e © 2014 SAGE Publications
- 6. Assessing Reliability of Measures • Test - retest. • Split half. • Intercoder or observer reliability. Introducing Communication Research 2e © 2014 SAGE Publications
- 7. Assessing Validity of Measures • Content or ‘face’ - “looks OK.” • Expert or panel - “looks OK’” to experts. • Construct - theoretically OK. • Convergent - agrees with similar measures. • Divergent - low agreement with different measures. • Predictive - predicts “real world” outcomes. Introducing Communication Research 2e © 2014 SAGE Publications
- 8. Likert Scale Strongly Strongly Agree Agree Neutral Disagree Disagree 1. Hybrid vehicles are powerful. ___ ____ ____ ____ _____ 2. Hybrid vehicles reduce dependency on foreign oil. ___ ____ _____ ____ _____ Introducing Communication Research 2e © 2014 SAGE Publications
- 9. Semantic Differential Scale The XKJ Bogbuster 300 is Powerful- - - - Weak Expensive - - - Cheap Beautiful - - - Ugly Introducing Communication Research 2e © 2014 SAGE Publications
- 10. Proprietary Measures • Tests and measures developed as commercial products. • Copyright. • May not be used without permission. Examples - ▫ SATs ▫ GREs ▫ vocational tests Introducing Communication Research 2e © 2014 SAGE Publications
- 11. Chapter Summary • Measures must have – ▫ Validity and reliability. • Measures exist at four levels – ▫ nominal — ordinal — interval — ratio. • Two common scales – ▫ Likert ▫ semantic differential. Introducing Communication Research 2e © 2014 SAGE Publications
- 12. Vocabulary Review Introducing Communication Research 2e © 2014 SAGE Publications