ML 4202 Chapter 10 Measurement Process is assigning numbers or labels to persons objects or events in accordance with specific rules for representing quantities or qualities of attributes Rule Guide method or command that tells a researcher what to do A problem often encountered with rules is a lack of clarity or specificity The steps a researcher should take to measure a phenomenon 1 Identify the Concept of Interest A concept is an abstract idea generalized from particular facts It is a category of thought used to group sense data together as if they were the same 2 Develop a Construct Constructs are specific types of concepts that exist at higher levels of abstraction than do everyday concepts Ex Brand loyalty high involvement purchasing social class personality and channel power 3 Define the Concept Constitutively Constitutive is a statement of the meaning of the central idea or concept under study establishing it s boundaries 4 Define the Concept Operationally Operational specifies which observable characteristics will be measured and the process for assigning a value to the concept Attitude enduring organization of motivational emotional perceptual and cognitive processes with respect to some aspect of the environment Construct equivalence Deals with how people see understand and develop measurements of a particular phenomenon 5 Develop a Measurement Scale Scale set of symbols or numbers so constructed that the symbols or numbers can be assigned by a rule to the individuals or their behaviors or attitudes to whom the scale is applied A sales person who feels he knows exactly how he is supposed to interact with customers would mark very certain for that item on the scale a Nominal scales Are among those most commonly used in marketing research Nominal name like indicating that the numbers assigned to objects or phenomena area naming or classifying them but have no true number value that is the numbers cannot be ordered added or divided Ex Gender and geographic area b Ordinal scales Scales that maintain the labeling characteristics of nominal scales and have the ability to order data Ranking is the objective of an ordinal scale typically a very certain to very uncertain scale Interval scales Scales that have the characteristics of ordinal scales plus equal intervals between points to show relative amounts they may include an arbitrary zero point Ex Fahrenheit and Celsius scales the freezing point of water is zero on one scale and 32 degrees on the other c d Ratio scales Scales that have the characteristics of interval scales plus a meaningful zero point so that magnitudes can be compared arithmetically 6 Evaluate the Reliability and Validity of the Measurement M A E where E errors Errors can be either random or systematic Systematic error results in a constant bias in the measurements caused by the faults in the measurement instrument or process For example if a faulty ruler on which one is actually one and a half inches is used in Pillsbury s test kitchens to measure the height of chocolate cakes baked with alternative recipes all cakes will be recorded at less than their actual height a Reliability Degree to which measures are free from random error and therefore provide consistent data b Test retest reliability Ability of the same instrument to produce consistent results when used a second time under conditions as similar as possible to the original conditions c Stability Lack of change in results from test to retest d Equivalent from reliability Determined by measuring the e correlation of the scores on the two instruments Internal consistency reliability Ability of an instrument to produce similar results when used on different samples during the same time period to measure a phenomenon f Split half technique Method of assessing the reliability of a scale by dividing the total set of measurement items in half and correlating the results g Validity The degree to which what the researcher was trying to measure was actually measured h Face validity The weakest form of validity It is concerned with the degree to which a measurement seems to measure what it is supposed to measure Face validity can refer to the subjective agreement of researchers experts or people familiar with the market product or industry that a scale logically appears to be accurately reflecting what it is supposed to measure i Content validity The representativeness or sampling adequacy of the content of the measurement instrument j Criterion related validity Degree to which a measurement instrument can predict a variable that is designated a criterion k Predictive validity Degree to which a future level of a criterion variable can be forecast by a current measurement scale l Concurrent validity Degree to which another variable measured at the same point in time as the variable of interest can be predicted by the measurement instrument m Construct validity Degree to which a measurement instrument represents and logically connects via the underlying theory the observed phenomenon to the construct Might think of construct validity as a labeling issue n Convergent validity Degree of correlation among different measurement instruments that purport to measure the same construct o Discriminant validity Measure of the lack of association among constructs that are supposed to be different