Ahmed Alsanousi
CSC 464
 Existing instruments
 Oscilloscope
 Re-use rating scale
 Create an instrument
 Survey
 Checklist
 Paper and pencil
 Tangible and intangible
 Measurement is limiting the data of any phenomenon –substantial or insubstantial–
so that those data may be interpreted and, ultimate, compared to a particular
qualitative or quantitative standard.
 Nominal Scales
 Ordinal Scales
 Interval Scales
 Ratio Scales
 Comes from Latin “nomen” means Name
 Used to Limits the data
 Example: Boys & girls in class
 Statistical procedures could be used
 Mode: for most frequent occurrence
 Percentage: part of total
 Chi-square test: compare occurrence between categories
 > (greater than) < (less than)
 Used to rank-order our data
 Example: Classification by education degree
 Statistical procedures could be used
 Median: determine half-way
 Percentile rank: determine position of item in a group
 Two features
1.
2.
Has equal units of measurements
Zero point is arbitrarily
 Example: Temperature
 Statistical procedures could be used
 Mean
 Standard deviation
 Two features
1.
2.
Has equal units of measurements
Zero point is an absolute zero
 Example: Ruler
 Rarely used outside physical science
 Can express values in multiples or fractions
 If you can say that
 One object is different from another
 you have a nominal scale
 One object is bigger or better or more of anything than another
 You have a ordinal scale
 One object is so many units more than another
 You have a interval scale
 One object is so many times as big or bright or tall or heavy as another
 You have a ratio scale
 Reliability is the consistency with which a measuring instrument yields a certain,
consistent result when the entity being measured hasn’t changes
 Example: waistline tape measure
 Interrater reliability
 Two testers, same result
 Test-retest reliability
 Retest in different occasions, same result
 Equivalent forms reliability
 Different versions or instrument, same result
 Internal consistency reliability
 Different items within instrument, same result
1.
Getting two measures by using one form of reliability
2.
Calculate how similar are the results