measurement
DESCRIPTION
MEASUREMENT. An attempt to provide an objective estimate of a natural phenomenon e.g. measuring height or weight. Measurement scales. Nominal Scales Categories -- mutually exclusive and collectively exclusive. Ordinal Scales Rank order – e.g. most important to least important. - PowerPoint PPT PresentationTRANSCRIPT
04/22/23Marketing Research 1
An attempt to provide an objective estimate of a natural phenomenon◦ e.g. measuring height
◦ or weight
04/22/23Marketing Research 2
Nominal Scales ◦ Categories -- mutually exclusive and collectively exclusive.
Ordinal Scales ◦ Rank order – e.g. most important to least important.
Interval Scales ◦ Ordinal + the intervals between data points are equal.
Ratio Scales ◦ Above + a meaningful absolute zero or origin.
04/22/23Marketing Research 3
How could you measure height using the following levels of measurement?◦ Nominal Scales ◦ Ordinal Scales ◦ Interval Scales ◦ Ratio Scales
04/22/23Marketing Research 4
Evaluate my bathroom scale:
Is it ACCURATE?
04/22/23Marketing Research 5
Consistent results over time.
Measures are free from random error.
Test-Retest Reliability:
Obtained by repeating the measurement using the same instrument under as nearly the same conditions as possible.
04/22/23Marketing Research 6
Addresses the issue of whether what we tried to measure was actually measured.
How do I know if my bathroom scale is valid?
That is, does 160 really MEAN anything?
How could I know this with my bathroom scale?
1. JUST using the same scale
2. Using ANOTHER scale.
04/22/23Marketing Research 7
• Face validity• Content validity• Criterion-Related Validity• Predictive Validity• Concurrent Validity• Construct Validity• Convergent Validity• Discriminant ValidityAll types of validity are related.
04/22/23Marketing Research 8
• Situation 1: A lack of reliability
• my scale varies a lot (150, 160, 170)• Situation 2:
High reliability, but lacks validity• My scale always shows 160, but other scales are different
• Situation 3: Reliable, consistent, and valid
• ALL scales show a consistent 160
04/22/23Marketing Research 9
Scaling Defined
In order to decrease noise:
you measure something several times
• Unidimensional scaling
• Multidimensional scaling Graphic Rating Scales
Present to respondents with a graphic continuum typically anchored by two extremes
04/22/23Marketing Research 10