Post on 18-Jul-2015
Meaning of Measurement and Scaling
Measurement: The term ‘measurement’ means assigning numbers or some other symbols to the characteristics of certain objects. When numbers are used, the researcher must have a rule for assigning a number to an observation in a way that provides an accurate description.
Scaling: Scaling is an extension of measurement. Scaling involves creating a continuum (range) on which measurements on objects are located.
ATTITUDEThe dictionary meaning of attitude is ‘settled
behavior, as indicating opinion’.Thurstone defined attitude as “ the sum total of
man inclinations and feelings, prejudice or bias, preconceived notions, ideas, fears, threats and conviction about some topic.”
An attitude is the degree of positive or negative effect associated with some psychological object.
CHARACTERISTICS OF SCALESCHARACTERISTICS OF SCALES
DESCRIPTION:FOR INSTANCE, “YES” OR “NO”, FOR INSTANCE, “YES” OR “NO”, “AGREE” OR “DISAGREE” AND THE NUMBER OF “AGREE” OR “DISAGREE” AND THE NUMBER OF YEARS OF A RESPONDENT’S AGE YEARS OF A RESPONDENT’S AGE
ORDER REFERS TO THE RELATIVE SIZES. Such as RELATIVE SIZES. Such as “GREATER THAN”“GREATER THAN” “LESS THAN” AND “EQUAL TO” .“LESS THAN” AND “EQUAL TO” .
A SCALE HAS THE CHARACTERISTIC OF DISTANCE WHEN ABSOLUTE DIFFERENCES BETWEEN THE ABSOLUTE DIFFERENCES BETWEEN THE DESCRIPTORSDESCRIPTORS ARE KNOWN AND MAY BE EXPRESSED IN UNITS. EXPRESSED IN UNITS. A THREE CAR FAMILY OWNS A A THREE CAR FAMILY OWNS A ONE MORE AUTOMOBILE THAN A TWO CAR FAMILY.ONE MORE AUTOMOBILE THAN A TWO CAR FAMILY.
A SCALE IS SAID TO HAVE A CHARACTERISTIC OF ORIGINORIGIN IF THERE IS A UNIQUE BEGINNINGUNIQUE BEGINNING OR TRUE TRUE ZEROZERO POINT FOR THE SCALE.
NOMINAL SCALENOMINAL SCALE
NOMINAL SCALES ARE DEFINED AS THOSE THAT USE ONLY LABEL; THAT IS, THEY POSSESS ONLY THE CHARACTERISTIC OF DESCRIPTION.DESCRIPTION.
Example: Example: DO YOU AGREE OR DISAGREE THAT “DELTA IS READY WHEN YOU ARE”?
AGREE DISAGREEEXAMPLESEXAMPLES
DESIGNATIONS AS TO RACE, RELIGION, TYPE OF DWELLING GENDER BRAND LAST PURCHASED ANSWERS THAT INVOLVE YES-NO, AGREE-DISAGREE OR ANY OTHER INSTANCE IN WHICH DESCRIPTORS CAN NOT BE
DIFFERENTIATED EXCEPT QUALITATIVELY
ORDINAL SCALE
AN ORDINAL SCALE IS OBTAINED BY RANKING OBJECTSRANKING OBJECTS OR ARRANGING THEM IN ORDER IN ORDER WITH REGARD TO SOME COMMON COMMON VARIABLEVARIABLE
Question: PLEASE RANK EACH BRAND IN TERMS OF YOUR PLEASE RANK EACH BRAND IN TERMS OF YOUR PREFERENCE PLEASE PLACE “1” BY YOUR FIRST CHOICE, A “2” PREFERENCE PLEASE PLACE “1” BY YOUR FIRST CHOICE, A “2” BY YOUR SECOND CHOICE, AND SO ONBY YOUR SECOND CHOICE, AND SO ON
I.I. SONYSONY
II.II. VIDEOCONVIDEOCON
III.III. SAMSUNGSAMSUNG
IV.IV. LGLG
V.V. BPLBPL
VI.VI. PHILLIPSPHILLIPS
INTERVAL SCALEINTERVAL SCALE
INTERVAL SCALES ARE THOSE IN WHICH THE DISTANCEDISTANCE BETWEEN EACH DESCRIPTOR IS KNOWN.
IF YOU WERE ASKED TO EVALUATE A STORE’S SALES PEOPLE BY IF YOU WERE ASKED TO EVALUATE A STORE’S SALES PEOPLE BY SELECTING A SINGLE DESIGNATION FROM THE LIST OFSELECTING A SINGLE DESIGNATION FROM THE LIST OF
EXTREMELY FRIENDLY VERY FRIENDLY SOME WHAT FRIENDLY SOME WHAT UNFRIENDLY VERY UNFRIENDLY EXTREMELY UNFRIENDLYTHE RESEARCHER WOULD PROBABLY ASSUME THAT EACH
DESIGNATION WAS ONE UNIT AWAY FROM THE PRECEDING ONE
a
RATIO SCALERATIO SCALE
RATIO SCALES ARE THE ONES IN WHICH TRUE ZERO ORIGINTRUE ZERO ORIGIN EXISTS—SUCH AS
-ACTUAL NUMBER OF PURCHASES IN A CERTAIN TIME PERIOD,
-RUPEES SPENT, MILES TRAVELED ETC.
examples
PLEASE INDICATE YOUR AGE
--- YEARS
HOW MUCH DO YOU THINK A TYPICAL PURCHASER OF A Rs. 5 LAKH TERM HOW MUCH DO YOU THINK A TYPICAL PURCHASER OF A Rs. 5 LAKH TERM LIFE INSURANCE POLICY PAYS PER MONTH THAT POLICY?LIFE INSURANCE POLICY PAYS PER MONTH THAT POLICY?
Rs.__________
APPROXIMATELY HOW MANY TIMES IN THE LAST MONTH HAVE YOU APPROXIMATELY HOW MANY TIMES IN THE LAST MONTH HAVE YOU PURCHASED ANY THING OVER Rs.1000 IN VALUE AT NANZ STORE?PURCHASED ANY THING OVER Rs.1000 IN VALUE AT NANZ STORE?
0 1 2 3 4 5 MORE ( SPECIFY_ )
Nominal, Ordinal, Interval, and Ratio Scales Provide Different InformationNominal, Ordinal, Interval, and Ratio Scales Provide Different Information
RELATIONSHIP BETWEEN SCALES AND SCALING PROPERTIES
SCALING PROPERTIESSCALING PROPERTIES
SCALE DESCRIPTION ORDER DISTANCE SCALE DESCRIPTION ORDER DISTANCE ORIGINORIGIN
NOMINAL YES NO NO NOMINAL YES NO NO NONO
ORDINAL YES YES NO ORDINAL YES YES NO NONO
INTERVAL YES YES YES INTERVAL YES YES YES NONO
RATIO YES YES YES RATIO YES YES YES YES YES
Comparative scales – In comparative scales it is assumed that respondents make use of a standard frame of reference before answering the question.
Example:-
Formats of Comparative Scales –
Paired comparison scales
Rank order scale
Constant sum rating scale
Q-sort technique
Paired comparison scale
It is sometimes the case that marketing researchers wish to find out which are the most important factors in determining the demand for a product. Conversely they may wish to know which are the most important factors acting to prevent the widespread adoption of a product.
For example, the respondent is suppose to ask j\his prefernce amongest 5 brands of tea A,B,C,D and E. than the pair comparison involves AB,AC, AD, AE,BC.BD,BE,CD,CE,DE.
Another example:
Rank order scaleRequires respondent to order stimulus w.r.t.
Some designated property of studyExample: Rank 6 detergent brands on
“gentleness on the hands". Normally the respondent is asked to order K/N i.e. Rank top 3 brands (=K) out of the 6 brands (=N)Implicitly assumes (a) respondent has experience on all the brands on the same attribute (b) respondents ranking will correctly reflect his preference
Non-Comparative Scales – In the non-comparative scales, the respondents do not make use of any frame of reference before answering the questions.
1) Graphic Rating Scale – This is a continuous scale and the respondent is asked to tick his preference on a graph.
Examples:
Itemized rating scale – In the itemized rating scale, the respondents are provided with a scale that has a number of brief descriptions associated with each of the response categories. There are certain issues that should be kept in mind while designing the itemized rating scale.
Number of categories to be usedOdd or even number of categoriesBalanced versus unbalanced scalesTypes of ITEMIZED RATING SCALES
I. LIKERT SCALEII. SEMANTIC DIFFERENTIAL SCALEIII. STAPEL SCALEIV. THURSTONE SCALE
Likert scale
The respondents are given a certain number of items (statements) on which they are asked to express their degree of agreement/disagreement.
This is also called a summated scale because the scores on individual items can be added together to produce a total score for the respondent.
An assumption of the Likert scale is that each of the items (statements) measures some aspect of a single common factor, otherwise the scores on the items cannot legitimately be summed up.
In a typical research study, there are generally 25 to 30 items on a Likert scale.
Semantic Differential Scale
This scale is widely used to compare the images of competing brands, companies or services.
Here the respondent is required to rate each attitude or object on a number of five-or seven-point rating scales.
This scale is bounded at each end by bipolar adjectives or phrases.
The difference between Likert and Semantic differential scale is that in Likert scale, a number of statements (items) are presented to the respondents to express their degree of agreement/disagreement. However, in the semantic differential scale, bipolar adjectives or phrases are used.
SLIDE 7-20
RESEARCH METHODOLOGY CONCEPTS AND CASES
DR D
EEPA
K CH
AWLA
DR
NEEN
A SO
NDHI
Classification of ScalesExample of Semantic Differential Scale: (Pictorial Profile)
Thurstone scales
The Thurstone scale is made up of statements about a particular issue and each statement has a numerical value indicating the respondent's attitude about the issue, either favorable or unfavorable. People indicate which of the statements with which they agree and the average response is computed.
First, you must be very clear about exactly what it is you’re trying to measure. Then, collect statements on the topic ranging from attitudes that are favorable to unfavorable.
Example: Marriage of a MinorExample statements areIt’s should be against the law.There’s absolutely nothing wrong with it.Marriage is between a man and a woman.It should be a sin.It should be legalized.It can harm children.It’s just horrible.It can’t do any harm.It destroy child life.
Measurement ErrorThis occurs when the observed measurement on a construct or concept deviates from its true values.
Reasons
Mood, fatigue and health of the respondent
Variations in the environment in which measurements are taken
A respondent may not understand the question being asked and the interviewer may have to rephrase the same. While rephrasing the question the interviewer’s bias may get into the responses.
Some of the questions in the questionnaire may be ambiguous errors may be committed at the time of coding, entering of data from questionnaire to the spreadsheet
Criteria for good measurementReliability
Reliability is concerned with consistency, accuracy and predictability of the scale.
Methods to measures ReliabilityTest–retest reliabilitySplit-half reliabilityCronbach’s Alpha
Criteria for good measurementValidity
The validity of a scale refers to the question whether we are measuring what we want to measure.
Different ways to measure Validity
Content validity
Concurrent validity
Predictive validity
Sensitivity
Sensitivity refers to an instrument’s ability to accurately measure the variability in a concept.