Research Methodology Lecture No : 10 (Measurement of Variables/Scales)

Recap Measurement is necessary to give answers or to the research question , or to test our hypotheses. The opeationalizing of certain subjective variables are necessary for measurement. The abstract concepts are broken down to dimensions and its elements. Questions are formulated on them Not to confuse dimensions with antecedents

Scales and Measurement We have operationalized the concepts and converted them into dimensions and elements We also have attached questions with these elements against which we would collect some data. Each question needs to measured

Measurement is the process of assigning numbers or labels to objects, persons, states of nature, or events. Done according to set of rules that reflect qualities or quantities of what is being measured.

Measurement means that scales are used. Scales are a set of symbols or numbers, assigned by rule to individuals, their behaviors, or attributes associated with them

Types of Scales Four types of scales are used in research, each with specific applications and properties. The scales are Nominal Ordinal Interval Ratio

Nominal Scale: Simply the Nominal scale is count of the objects belonging to different categories. Ordinal Scale: The ordinal scale positions objects in some order ( such as it indicates that pineapples are juicer then apples and oranges are even more juicer than pineapples)

Interval Scale: It can gives us information as to what extent(level) one is juicer than the other. How much better is the pineapple than the apple and orange is better than the pine apple. Is pine apple only marginally better than the apple . Ratio Scale: It is most comprehensive scale, has all characteristics of other scales.

Nominal Scales Nominal scales are used to classify objects, individuals, groups, or even phenomena. Examples of nominal variables: Gender State of residence Country Ethnicity

Nominal scales are mutually exclusive (meaning that those items being classified will fit into one classification). These scales are also collectively exhaustive, (meaning that every element being classified can fit into the scale).

As it might appear on a questionnaire, examples of nominally scaled questions included: What is your class rank at CIIT? 1. Freshman 3. Junior 2. Sophomore 4. Senior

The numbers themselves do not have meaning (we could have used letters, too), They are used just to identify the possible responses to the question. Thus, in evaluating responses to this you cannot use the mean. Permitted statistics; frequencies (% and counts, modes )

Nominal scale is always used for obtaining personal data such as gender or department in which one works, where grouping of individuals or objects is useful, as shown below. 1. Your gender 2. Your department ___Male ___Production ___Female ___Sales ___Accounting ___Finance ___Personnel ___R & D ___Other (specify)

Ordinal Scales These scales allow for labeling (or categorization) as in nominal scales, but they also allow for ranking. Example: Rate these vacation destinations in terms of how much you would like to visit from one to five with one your most preferred and five your least preferred. Bermuda Florida Hawaii Aspen London

This type of scale can provide information about some item having more or less of an attribute than others, but no information on the degree of this. Permitted statistics: Frequencies, median, mode

Ordinal scale is used to rank the preferences or usage of various brands of a product by the individuals and to ranks order individuals, objects, or events as per the examples below.

Rank the following personnel computers with respect their usage in your office, assigning the number 1 to the most used system, 2 to the next most used, and so on. If a particular system is not used at all, in your office, put a 0 next to it. ____Apple ____Hewlett Packard ____Compaq ____IBM ____Comp USA ____Packard Bell ____Dell Computer ____Sony ____Gateway ____Toshiba

Interval Scales Contains the information available in ordinal scales (ranking) but with the added benefit of magnitude of ranking. Interval scales have equal distances between the points of a scale. These scales can contain a zero point, but they are subjective and are not meaningful (0° C = 32° F). Temperature is an example of a interval scale Permitted statistics; mean, median, mode, as well as more advanced tests.

On a scale of one to five, with five meaning you strongly agree, and one meaning you strongly disagree consider this statement ‘I believe my college education has prepared me well to begin my career’. 5 1 2 3 4 Strongly disagree Somewhat disagree Somewhat agree Strongly agree Neither 4/21/2017

Ratio Scale The most comprehensive scale Has all of the characteristics of the other three with the additional benefit of an absolute, meaningful zero point. Examples include: Weight Sales volume Income Age Permitted statistics same as with interval data.

A ratio variable, has all the properties of an interval variable, and also has a clear definition of 0.0. When the variable equals 0.0, there is none of that variable. Variables like height, weight, enzyme activity are ratio variables.

Temperature, expressed in F or C, is not a ratio variable Temperature, expressed in F or C, is not a ratio variable. A temperature of 0.0 on either of those scales does not mean 'no temperature'. However, temperature in Kelvin is a ratio variable, as 0.0 Kelvin really does mean 'no temperature'.

Ratio scales are usually used in organization research when exact numbers on objective as opposed to subjective factors are called for, as in the following question: How many other organizations did you work for before Date joining this system? 4/21/2017

Please indicate the number of children you have in each of the following categories? ---- below 3 years ---- between 3 and 6 ---- over 6 years but under 12 ---- 12 years and over How many retail outlets do you operate?

Comparison between scales The researcher would like to know what is the percentage of people who like Pepsi, 7up, Coke, Miranda? Choose the soft Drink you want to order. Pepsi 7Up Coke Marinda

The researcher would like to know among the 4 soft dinks which they prefer the most ,assigning 1 to most and 4 to the least Pepsi 7Up Coke Marinda

The researcher would like to know what extent the 4 drinks are liked On a scale of one to five, with five meaning you strongly like, and one meaning you strongly dislike consider this statement ‘I like/dislike this soft drink ’. Pepsi 1 2 3 4 5 Coke 1 2 3 4 5 7up 1 2 3 4 5 Marinda 1 2 3 4 5

The researcher would like to know how many Pepsi , Mrindia , etc you consume in a month 7Up: _____ Coke: _____ Marinda:_____

Balanced or Unbalanced How good a car is Honda? Very bad Bad Neither good nor bad Good Very good Poor Fair Good Very good Excellent

Forced or Unforced Choices How good a car is Honda? Very bad Bad Neither good nor bad Good Very good Very bad Bad Neither good nor bad Good Very good No opinion Don’t know

Rating Scales

Simple Category (Dichotomous) Scale I plan to purchase a laptop in the 12 months. Yes No This scale is also called a dichotomous scale. It offers two mutually exclusive response choices. In the example shown in the slide, the response choices are yes and no, but they could be other response choices too such as agree and disagree.

Multiple-Choice, Single Response Scale What newspaper do you read most often for financial news? East City Gazette West City Tribune Regional newspaper National newspaper Other (specify:_____________) When there are multiple options for the rater but only one answer is sought, the multiple-choice, single-response scale is appropriate. The other response may be omitted when exhaustiveness of categories is not critical or there is no possibility for an other response. This scale produces nominal data.

Multiple-Choice, Multiple Response Scale What sources did you use when designing your new home? Please check all that apply. Online planning services Magazines Independent contractor/builder Designer Architect Other (specify:_____________) This scale is a variation of the last and is called a checklist. It allows the rater to select one or several alternatives. The cumulative feature of this scale can be beneficial when a complete picture of the participant’s choice is desired, but it may also present a problem for reporting when research sponsors expect the responses to sum to 100 percent. This scale generates nominal data.

Likert Scale The Internet is superior to traditional libraries for comprehensive searches. Strongly disagree Disagree Neither agree nor disagree Agree Strongly agree The Likert scale was developed by Rensis Likert and is the most frequently used variation of the summated rating scale. Summated rating scales consist of statements that express either a favorable or unfavorable attitude toward the object of interest. The participant is asked to agree or disagree with each statement. Each response is given a numerical score to reflect its degree of attitudinal favorableness and the scores may be summed to measure the participant’s overall attitude. Likert scales may use 5, 7, or 9 scale points. They are quick and easy to construct. The scale produces interval data. Originally, creating a Likert scale involved a procedure known as item analysis. Item analysis assesses each item based on how well it discriminates between those people whose total score is high and those whose total score is low. It involves calculating the mean scores for each scale item among the low scorers and the high scorers. The mean scores for the high-score and low-score groups are then tested for statistical significance by computing t values. After finding the t values for each statement, they are rank-ordered, and those statements with the highest t values are selected. Researchers have found that a larger number of items for each attitude object improves the reliability of the scale.

Semantic Differential The semantic differential scale measures the psychological meanings of an attitude object using bipolar adjectives. Researchers use this scale for studies of brand and institutional image. The method consists of a set of bipolar rating scales, usually with 7 points, by which one or more participants rate one or more concepts on each scale item. The scale is based on the proposition that an object can have several dimensions of connotative meaning. The meanings are located in multidimensional property space, called semantic space. It is efficient and easy for securing attitudes from a large sample. Attitudes may be measured in both direction and intensity. The total set of responses provides a comprehensive picture of the meaning of an object and a measure of the person doing the rating. It is standardized and produces interval data. A measure of attitudes that consists of a series of seven-point rating scales that use bipolar adjectives to anchor the beginning and end of each scale.

Numerical Scale Numerical scales have equal intervals that separate their numeric scale points. The verbal anchors serve as the labels for the extreme points. Numerical scales are often 5-point scales but may have 7 or 10 points. The participants write a number from the scale next to each item. It produces either ordinal or interval data. An attitude rating scale similar to a semantic differential except that it uses numbers, instead of verbal descriptions, as response options to identify response positions.

Stapel Scales The Stapel scale is used as an alternative to the semantic differential, especially when it is difficult to find bipolar adjectives that match the investigative question. In the example, there are three attributes of corporate image. The scale is composed of the word identifying the image dimension and a set of 10 response categories for each of the three attributes. Stapel scales produce interval data. A measure of attitudes that consists of a single adjective in the center of an even number of numerical values.

Constant-Sum Scales A measure of attitudes in which respondents are asked to divide a constant sum to indicate the relative importance of attributes; respondents often sort cards, but the task may also be a rating task. The constant-sum scale helps researchers to discover proportions. The participant allocates points to more than one attribute or property indicant, such that they total a constant sum, usually 100 or 10. Participant precision and patience suffer when too many stimuli are proportioned and summed. A participant’s ability to add may also be taxed. Its advantage is its compatibility with percent and the fact that alternatives that are perceived to be equal can be so scored. This scale produces interval data.

Graphic Rating Scales The graphic rating scale was originally created to enable researchers to discern fine differences. Theoretically, an infinite number of ratings is possible if participants are sophisticated enough to differentiate and record them. They are instructed to mark their response at any point along a continuum. Usually, the score is a measure of length from either endpoint. The results are treated as interval data. The difficulty is in coding and analysis. Other graphic rating scales use pictures, icons, or other visuals to communicate with the rater and represent a variety of data types. Graphic scales are often used with children. A measure of attitude that allows respondents to rate an object by choosing any point along a graphic continuum.