research methodology.......ppt
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Research Methodology.......PPTTRANSCRIPT
UNIT NO – 5 Measurement
•Concept of Measurement• Levels of Measurement – 1. Nominal
2. Ordinal
3. Interval
4. Ratio
• Problems in Measurement
• Validity & Reliability
Measurement In business research, measurement of variables is a one
of the requirement
Problem – Defining what is to be measured, and how it is to be accurately and reliably measured
Some things (or concepts) which are inherently abstract in their nature (e.g. job satisfaction, employee morale, brand loyalty of consumers) are more difficult to measure than concepts which can be assigned numerical values (e.g. sales volume for employees X, Y and Z)
Measurement
Measurement means assigning numbers or other symbols to characteristics of object according to certain pre-specified rules.
Numbers are usually assigned for two reasons-
1. Number permit statistical analysis of the resulting data.
2. Number facilitate the communication of measurement rules and results.
A scale is basically a continuous spectrum or series of categories and has been defined as any series of items that are arranged progressively according to value or magnitude, into which an item can be placed according to its quantification.
Four popular Levels of Measurement in business research are:– Nominal scales
– Ordinal scales
– Interval scales
– Ratio scales
A nominal scale is the simplest of the four scale types and in which the numbers or letters assigned to objects serve as labels for identification or classification
Example:
Males = 1, Females = 2 Sales Zone A = Bombay, Sales Zone B = Delhi Drink A = Pepsi Cola, Drink B = 7-Up, Drink C = Miranda
An ordinal scale is one that arranges objects or alternatives according to their magnitude. This scale provide information of the ordered relationship.
Examples:
Career Opportunities = Moderate, Good, Excellent Investment Climate = Bad, inadequate, fair, good, very good Merit = A grade, B grade, C grade, D grade
A problem with ordinal scales is that the difference between categories on the scale is hard to quantify, i.e., excellent is better than good but how much is excellent better?
An interval scale is a scale that not only arranges objects or alternatives according to their respective magnitudes, but also distinguishes this ordered arrangement in units of equal intervals (i.e. interval scales indicate order (as in ordinal scales) and also the distance in the order)
Examples: Consumer Price IndexTemperature Scale in Fahrenheit
it is useful for statistical treatment, also has the power of nominal and ordinal data.
A ratio scale is a scale that possesses absolute rather than relative qualities. Ratio scale is the highest scale, it possesses all the properties of the nominal, ordinal, & interval scale.
Examples: MoneyWeightDistanceTemperature on the Kelvin Scale
Ratio scales allow comparisons of the differences of magnitude (e.g. of attitudes) as well as determinations of the actual strength of the magnitude
Type of Scale
Numerical Operation Descriptive Statistics
Nominal Counting Frequency in each category, percentage in each category, mode
Ordinal Rank Ordering Median, range, percentile ranking
Interval Arithmetic Operations on
Intervals between numbers
Mean, standard deviation, variance
Ratio Arithmetic Operations on actual quantities
Geometric mean, coefficient of variation
Problems in Measurement in Management Research
Sources of errors in measurement
1. Instrument
2. Measurer
3. Situation
4. Respondent
Criteria for Good MeasurementReliability – Reliability is the degree to which
measures are free from error so that they give same results when repeat measurements are made under constant conditions.
To be reliable a measurement instrument must have two characteristics-
1.It must have a small random error component.
2.To provide reliable measurements of a construct, an instrument must measure that construct alone- and only one dimension
Validity – Validity is the ability of a scale or measuring instrument to measure what it is intended to measure.
e.g. is absenteeism from work a valid measure of job satisfaction or are there other influences.
Validity means the ability to produce findings that are in agreement with conceptual or theoretical values. Validity refers to the success of the scale in measuring what is meant to be measured .
Unit - 6 Attitude Scaling Techniques
• Concept of scale• Rating Scale – 1. Likert Scale
2. Semantic Differential Scale
3. Constant Sum Scale
4. Graphic Rating Scale
• Ranking Scale- 1. Paired Comparison
2. Forced Ranking
Attitude
Measuring Attitude is a frequent undertaking in business research.
Attitude has three dimensions:
AffectiveComponent
AffectiveComponent
CognitiveComponent
CognitiveComponent
BehaviouralComponent
BehaviouralComponent
Components of Attitude Affective Component – Reflective of a person’s general
feelings or emotions towards an object or subject (like, dislike, love, hate)
Cognitive Component – Reflective of a person’s awareness of and knowledge about an object or subject (know, believe)
Behavioural Component – Reflective of a person’s intentions and behavioural expectations, and predisposition to action
Measuring Attitude
• It can be difficult to measure attitude, therefore, indicators such as verbal expression, physiological measurement techniques and overt behaviour are used for this purpose. The three different components of attitude may require different measuring techniques.
• Common techniques used in business research to determine attitude include rating, ranking, sorting and the choice technique.
Scaling Procedures for assigning numbers (or other
symbols) to properties of an object in order to impart some numerical characteristics to the properties in question.
Scaling Approaches:
• Unidimensional:– Measures only one attribute of a concept, respondent, or
object.
• Multidimensional:– Measures several dimensions of a concept, respondent, or
object
Types of Scales
• Non-comparative Scale:– Scales in which judgment is made without
reference to another object, concept, or person.
• Comparative Scale:– Scales in which one object, concept, or person
is compared with another on a scale.
1. Likert Scale
Scale consists of statements that express either a favorable or an unfavorable attitude towards the object of interest.
The respondent is asked to agree or disagree with each statement. Each response is given a numerical score to reflect its degree of attitude of favorableness and the scores may be totaled to measure the respondent’s attitude. This scale produces interval data.
A likert scale helps us compare one person’s score with a distribution of scares from a well defined group.
Ex- The home theatre sound quality is superior to other TV models.
1 Strongly Agree
2 Agree
3 Neither Agree nor Disagree
4 Disagree
5 Strongly Disagree
• The Likert scale, developed by Rensis Likert, is the most frequently used variation of the summated rating scale .
• It is easy and quick to construct, administer and use.
• Major disadvantage of the Likert scale is that it takes longer to complete than other itemized rating scales because respondents have to read each statement.
Steps in Likert Scale -• Write a large number of statements that concern the
particular attitudinal object being investigated. Most of these statements should be either moderately positive or moderately negative. Neutral items are generally avoided in these scales. The items should be evenly divided between positive and negative statements.
• Administer the pool of statements on a group of respondents who are similar to the population on whom the scale will be used.
• Assign scale values to the degrees of agreement or disagreement with each item. The particular values 1,2,3,4,5 and sometimes +2, +1, 0, -1, -2
• Calculate a total attitude score for each respondent using the same scaling procedure. The distribution of total scores is then used to refine the list of items, this step is called item analysis. Analyze the responses and select for the scale those items, which most clearly differentiate between the highest ( favourable attitude) and lowest scores (least favourable attitude).
• The statements remaining in the list are randomly ordered on the scale form.
• The scale is now administered on the respondents who are asked to indicate their degree of agreement with the items. A respondent’s total score is generated as the sum of its score on the each statement.
2. Semantic Differential scale
• This scale measures the psychological meaning of an attitude object and is a seven point scale with end points associated with bipolar labels that have semantic meaning.
• The scale is based on the proposition that an object can have several dimensions. The meanings are located in multidimensional property space, called semantic space.
• The preparation of a semantic differential scale for a study requires expressing the things that could be used to described the object and thus serves as a basis for attitude formation in terms of positive and negative statements.
Ex- Do you satisfy about SURF quality?
Dissatisfy :___:___:___:___:___:___:___: Satisfy
List of some bipolar adjectives –
Good – Bad, Honest – Dishonest,
Uncomfortable – Comfortable, Informal – Formal,Unorganized – Organized, Complex- Simple,Strong – Weak, Active – PassiveTrue – False, Heavy – Light,Unsuccessful – Successful, Hot - Cold
Steps in SD Scale
1. Select the concept. Concepts are chosen by judgment and reflect the nature of the investigative question.
2. Select bipolar word pairs appropriate to your needs. The scale should be relevant to the concept being judged.
3. Create the scoring system and assign a weight to each point on the scale. Most SD scales have 7 points
3. Constant Sum Scale
Constant Sum Scale is a comparative scaling technique in which respondent are required to allocate a constant sum of units such as points.
A scale that helps the researcher discover proportions is the Constant-sum scale. With a constant –sum scale, the participant allocates points to more than one attribute or property indicant, such they total a constant sum, usually 100 or 10.
• Ex- What features do you want in a car?
Sun roof ______Leather ______ABS Breaks ______CD Player ______ Total 100 points
4. Graphic Rating Scale
The graphic rating scale was originally created to enable researchers to discuss fine differences.
The graphic rating scale employs a line that has at its two extremes marked the extreme values of the attributes being measured. Scale points are also indicated at intermediate points along the line to help the rater ascertain his position
Measurement scales that include a graphic continuum, anchored by two extremes.
Extremely Extremely
Dissatisfied satisfied
1. Paired Comparison
Is a comparative scaling technique in which a respondent is presented with two objects at a time and asked to select one object in the pair according to some criterion. The data obtained are ordinal in nature.
Ex- there are 4 types of drinking- coke, Pepsi, sprite and orange. The respondent can prefer coke to sprite or Pepsi to orange.
2. Forced Ranking
In this method the respondent are asked to rank their choices as 1,2,3 …..
List attributes that are ranked relative to each other. This method is faster than paired comparisons and is usually easier and more motivating to the participant.
Ex- Rank the following in your order of preference. Place the no. 1 next to the most preferred, 2 by the second choice, and so forth.
Rank the management college in Pune university 1. NWIMSR, 2. MITSOM, 3.VIM 4.IBMR, 5. D.Y
PATIL
“Which drink doyou prefer:”
___Coke___Pepsi
___Coke___Sprite
___Pepsi___Sprite
What features do you want in a car?
Sun roof ______Leather ______ABS Breaks ______CD Player ______
Total 100 points
Measurement Scales
Measurement scales that include a graphic continuum, anchored by two extremes
The respondent selects an answer from a limited number of ordered categories.
Important Not Important 1 2 3 4 5
Important Not Important 1 2 3 4 5 6
Odd Scale
Even Scale
-5-4-3-2-1
High Value+1+2+3+4+5
“How do you like your pizza”?
Hot Cold Bland SpicyExpensive Inexpensive Fresh Frozen Natural Artificial Soggy Crisp Moist Dry
Is “soggy” prejudicial?
- - - - - - - - - - - - - - - - - -- - - - - - - - - - - - - - - - - -- - - - - - - - - - - - - - - - - -- - - - - - - - - - - - - - - - - -- - - - - - - - - - - - - - - - - -- - - - - - - - - - - - - - - - - -- - - - - - - - - - - - - - - - - -
• Uses Comparative Scaling:
• Put these fast food chains in order of preference:
• McDonalds• Burger King• Taco Bell
Honda is a good car brand:1 Agree2 Somewhat Agree3 Somewhat Disagree4.Disagree
1 Agree2 Somewhat Agree3 Somewhat Disagree4.Disagree
• Multiple response
• Single response
• Controlled response
Check all that apply
Check only one
Check the top three
•
•
•
Check all that apply
Check only one
Check the top three
Check all that apply
Check only one
Check the top three
How to Select a ScaleFour Things to Consider
• 1. The nature of the construct being measured
• 2. The value and pitfalls of open-ended questions
• 3. Balanced vs. Non-balanced• Balanced:
– Scales with equal numbers of positive & negative categories.• Non-balanced:
– Scales weighted towards one end or the other of the scale.
• 4. Forced vs. Non-forced• Having an odd vs. even number of response choices
Measuring Behavioral Intentions
Behavioural intentions relate to „will“, „shall“ or „may“ questions:
Examples:– I will purchase Product X– I shall change my job from 1st January 2006– I may participate in Training Workshop Z
The Behavioural Differential: This is an instrument for measuring the behavioural intentions of subjects towards an object or category of objects. Example:
A HousewifeWould ___ : ___ : ___ : ___ : ___ : ___ : ___ Would Not
Purchase this laundry detergent