Measurement Process
What is the difference between validity and reliability?
Validity measures whether a test measures what it’s supposed to
Reliability measures whether it produces consistent results.
What are the two main sources of measurement error? Explain each.
Systematic Error: a consistent pattern of error that affects measurement in a constant way; includes measurement & sampling error
Random Error: unpredictable “noise” during measurement
Which analysis can be done with a ratio scale?
Correlation and regression analysis
What scale maintains the labeling characteristics of nominal scale and can order data?
Ordinal
What distinguishes the four levels of measurement: nominal, ordinal, interval, and ratio?
Nominal: unique values
Ordinal: unique values + rank order
Interval: unique values + rank order + equal intervals
Ratio: unique values + rank order + equal intervals + meaningful absolute zero point