measurement and scales

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Measurement and Scales : 

Measurement and Scales By Lucell Larawan

Introduction : 

Introduction Measurement—consists of assigning numbers to empirical events, objects or properties, or activities in compliance with a set of rules. This definition implies that measurement is a three-part process: 1) Selecting observable empirical events. 2) Developing a set of mapping rules: a scheme for assigning numbers or symbols to represent aspects of the event being measured. 3) Applying the mapping rules to each observation of that event. Example: Researchers might want to measure the styling desirability of a new concept car. They interview a sample of visitors and assign their opinions to the following scale: What is your opinion of the styling of the concept CS? Very desirable 5 4 3 2 1 Very undesirable

Slide 3: 

Measurement must involve quantification– that is the assignment of numbers to objects to represent amounts or degrees of a property possessed by all of the objects. Our approach endorses that “numbers as symbols within a mapping rule” can reflect both qualitative and quantitative concepts. The goal of measurement—assigning numbers to empirical events in compliance with a set of rules—is to provide the highest-quality, lowest error data for testing hypotheses, estimation or prediction, or description. Researchers deduce from a hypothesis that certain conditions should exist. Then they measure these conditions in the real world.

Slide 4: 

Variables accept numerals or values for the purpose of testing and measurement. Concepts, constructs and variables may be defined descriptively or operationally. We need to come up with operational definition which defines a variable in terms of specific measurement and testing criteria. It must specify adequately the empirical information needed and how it will be collected. In addition, it must have the proper scope or fit for the research problem at hand.

What is measured? : 

What is measured? Variables may be classified as objects or properties. Objects—concepts of ordinary experience such as tangible items like furniture, laundry detergent, people or automobiles. Properties—characteristics of the object A person’s physical properties may be stated in terms of height, weight, and posture, among others. Psychological properties include attitudes and intelligence. Social properties include leadership ability, class affiliation, and status.

Measurement and scales : 

Measurement and scales In measuring, one devises some mapping rule and then translate the observation or property indicants using this rule. Mapping rules have four assumptions: 1) Numbers are used to classify, group, or sort responses. No order exists. 2) Numbers are ordered. One number is greater than, less than, or equal to another number. 3) Differences between numbers are ordered. The difference between any pair or numbers is greater than, less than, or equal to the difference between any other pair of numbers. 4) The number series has a unique origin indicated by the number zero. This is an absolute and meaningful zero point. Combinations of these characteristics of classification, order, distance, and origin provide four widely-used classifications of measurement scales: nominal, ordinal, interval, ratio.

Measurement scales : 

Measurement scales

Characteristics of good measurement : 

Characteristics of good measurement Validity—the extent to which a test measures what we actually wish to measure Reliability—has to do with the accuracy and precision of a measurement procedure Practicality—is concerned with a wide range of factors of economy, convenience, and interpretability

Summary of validity estimates : 

Summary of validity estimates

Summary or reliability Estimates : 

Summary or reliability Estimates

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