MEASUREMENT AND SCALING

MEASUREMENT AND SCALING

Presented By,Sona Sebastian

MBAS B College Chry

MEASUREMENT Measurement is defined as process of

associating numbers or symbols to observations obtained in a research study

These observation could be qualitative or quantitative.

It is difficult to measure abstract or qualitative characteristics than quantitative characteristics

It is easy to measure properties like weight ,height etc. by some standard unit of measurement

Continued…

But it is difficult to measure properties like motivation , honesty, customer’s perceptions, brand loyalty etc.

Example: We can record a person’s marital status as 1

,2 , 3 or 4 depending on whether the person is single, married , widowed or divorced. We cannot make comparison between these numbers but can be count each number

Classification of measurement scales

a) Nominal Scaleb) Ordinal Scalec) Interval Scale andd) Ratio Scale

The most widely used classification of measurement are :

Nominal Scale Nominal scale is the most elementary form of

measurement . It is simply a system of assigning number symbols to

elements in order to label them. For example , a population may be classified as males

and females. Males can be assigned numeral as 1 and females as 2 . Members of a labeled set can only be counted.

Mode is the only measure of central tendency that can be applied.

Chi – squire test is the most common test of statistical significance

Ordinal Scale Ordinal scale places elements in order. It ranks objects or elements from one largest

to smallest or first to last. For example: ranking of students according to

scores obtained by them. Ordinal scale represent which is greater and

which is lesser. Appropriate measure of central tendency is

median. Percentile is used for measuring dispersion

Interval Scale It assumes that the measurements are made in

equal units. i.e. gaps between whole numbers on the scale are

equal. e.g. Fahrenheit and Celsius temperature scales an interval scale does not have a true zero. e.g. A

temperature of "zero" does not mean that there is no temperature...it is just an arbitrary zero point.

Permissible statistics: count/frequencies, mode, median, mean, standard deviation

RATIO SCALE Ratio scale represnts the actual amount of

variables. Eg; measures of physical dimensions such as height, weight ,distance etc. similar to interval scales except that the ratio scale

has a true zero value. e.g. the zero point on a centimetre scale indicates

the complete absence of length or height allows to compare differences between numbers. Permits full arithmetic operation.

0

1

2

3

4

5

6

7

Examplesheight, weight, age, LengthtimeIncomeMarket share

1.What is your annual income before taxes? Rs;_______

2. How far is your workplace

from home? _______ miles

MEASUREMENT SCALESScale Basic

CharacteristicsCommon Examples

Marketing Examples

Nominal Numbers identify & classify objects

Social Security nos., numbering of football players

Brand nos., store types

Percentages, mode

Chi-square, binomial test

Ordinal Nos. indicate the relative positions of objects but not the magnitude of differences between them

Quality rankings, rankings of teams in a tournament

Preference rankings, market position, social class

Percentile, median

Rank-order correlation, Friedman ANOVA

Ratio Zero point is fixed, ratios of scale values can be compared

Length, weight Age, sales, income, costs

Geometric mean, harmonic mean

Coefficient of variation

Permissible Statistics Descriptive Inferential

Interval Differences between objects

Temperature (Fahrenheit)

Attitudes, opinions, index

Range, mean, standard

Product-moment

Classification of Scaling Techniques

Comparative scales;Involve the respondent directly comparing stimulus objects.

• e.g. How does Pepsi compare with Coke on sweetness

Noncomparative scales;Respondent scales each stimulus object independently of other objects

• e.g. How would you rate the sweetness of Pepsi on a scale of 1 to 10

Paired Comparison Scaling A respondent is presented with two objects and asked to

select one according to some criterion. The data obtained are ordinal in nature. Paired comparison scaling is the most widely-used

comparative scaling technique. It is given by the formula, N=[n(n - 1) /2] , where `N’ – number of judgements ` n’ – Number of stimuli or objects to be judged. Under the assumption of transitivity, it is possible to

convert paired comparison data to a rank order.

Rank Order Scaling Respondents are presented with several objects

simultaneously and asked to order or rank them according to their choices.

It is possible that the respondent may dislike the brand ranked 1 in an absolute sense.

Furthermore, rank order scaling also results in ordinal data.

It is easier and faster than the method of paired comparison

Constant Sum Scaling

It is used to assess the relative importance attached by a respondent to the stimulus objects.

The respondents gives certain points to each stimulus objects out of a fixed sum of points

The fixed sum is usually taken as 100, but it could be other value also.

Non comparitive

scaling techniques1.Continues rating or graphic

ratingRespondents rate the objects by placing a mark at the appropriate position on a line that runs from one extreme of the criterion variable to the other.

Itemized Rating Scales The respondents are provided with a scale

that has a number or brief description associated with each category.

The categories are ordered in terms of scale position, and the respondents are required to select the specified category that best describes the object being rated.

The commonly used itemized rating scales are the Likert, semantic differential, and Stapel scales.

The Likert Scale

The Likert scale requires the respondents to indicate a degree of agreement or disagreement with each of a series of statements about the stimulus objects.

  

The analysis can be conducted on an item-by-item basis (profile analysis), or a total (summated) score can be calculated.

When arriving at a total score, the categories assigned to the negative statements by the respondents should be scored by reversing the scale.

Response alternatives: “strongly agree”, “agree”, “uncertain”, “disagree”, and “strongly disagree”. Generally use either a 5- or 7-point scale

Semantic Differential Scales The semantic differential is a seven-point

rating scale with end points associated with bipolar labels that have semantic meaning.

The negative adjective or phrase sometimes appears at the left side of the scale and sometimes at the right.

This controls the tendency of some respondents, particularly those with very positive or very negative attitudes, to mark the right- or left-hand sides without reading the labels.

Individual items on a semantic differential scale may be scored on either a -3 to +3 or a 1 to 7 scale.

Stapel ScalesThe Stapel scale is a unipolar rating scale with ten categoriesnumbered from -5 to +5, without a neutral point (zero). This

scale is usually presented vertically.  

SEARS 

+5 +5+4 +4+3 +3+2 +2X+1 +1

HIGH QUALITY POOR SERVICE-1 -1-2 -2-3 -3-4X -4-5 -5

The data obtained by using a Stapel scale can be analyzed in the same way as semantic differential data.

Scale Basic Characteristics

Examples Advantages Disadvantages

Continuous Rating Scale

Place a mark on a continuous line

Reaction to TV

commercials

Easy to construct Scoring can be cumbersome unless computerized

Itemized Rating Scales

Likert Scale Degrees of

agreement on a 1 (strongly disagree) to 5 (strongly agree) scale

Measurement of attitudes

Easy to construct, administer, and understand

More time-consuming

Semantic Differential

Seven-point scale with bipolar labels

Brand, product, and company images

Versatile Controversy as to whether the data are interval

Stapel Scale

Unipolar ten-point scale, -5 to +5, without a neutralpoint (zero)

Measurement of attitudes and images

Easy to construct, administer over telephone

Confusing and difficult to apply

Basic Noncomparative Scales

1