MEASUREMENT SCALES

What is Scaling?

Scaling is assigning numbers to indicants of the properties of objects

Types of Response Scales

• Rating Scales
  
• Ranking Scales
  
• Categorization
  

Types of Rating Scales

• Simple category Numerical
  
• Multiple choice, single response Multiple rating
  
• Multiple choice, multiple response Fixed sum
  
• Likert scale Staple
  
• Semantic differential Graphic rating
  

Category Scale

• The category scale uses multiple items to elicit a single response.
  
• This uses the nominal scale.
  
• Example: where in northern California do you reside? North Bay, South Bay, East Bay, Peninsula, and other.
  

Likert Scale

• This is an interval scale and the differences in the responses between any two points on the scale remain the same.
  
• The responses over a number of items tapping a particular concept or variable are then summated for every respondent.
  
• Example: it is designed to examine how strongly subjects agree or disagree with statements on a 5-point scale for the work.
  

Semantic Differential Scale

• It is used to assess respondent's attitudes toward a particular brand, advertisement, object, or individual.
  
• This is treated as an interval scale.
  
• Several bipolar attributes are identified at the extremes of the scale such as Good-Bad, Strong-Weak, and Hot-Cold.
  
• Example: responsive-unresponsive, beautiful-ugly, and courageous-timid.
  

Numerical Scale

• It is similar to the semantic differential scale.
  
• The 5-point or 7-point scale are provided.
  
• Example: 7-point, extremely pleased-extremely displeased.
  

Itemized Rating Scale

• A 5-point or 7-point scale with anchors, as needed, is provided for each item.
  
• When a neutral point is provided, it is a balanced rating scale, and when it is not, it is an unbalanced rating scale.
  
• Research indicates that a 5-point scale is just as good as any, and that an increase from 5 to 7 or 9 points on a rating scale does not improve the reliability of the ratings.
  

Itemized Rating Scale (cont.)

• Example: 5 points, balanced rating scale with a neutral point.
  
• Example: 4 points, unbalanced rating scale without a neutral point.
  

Fixed or Constant Sum Scale

• The respondents are here asked to distribute a given number of points across various items.
  
• This is in the nature of an ordinal scale.
  
• Example: In choosing a toilet soap such as fragrance, color, shape, size, and texture of lather.
  

Stapel Scale

• This scale simultaneously measures both the direction and intensity of the attitude toward the items under study.
  
• This is does not have an absolute zero point, this is an interval scale.
  
• Example: supervisor's abilities such as adopting modern technology, product innovation, and interpersonal skill, from +3 to –3.
  

Graphic Rating Scale

• A graphical representation helps the respondents to indicate on this scale their answers to a particular question by placing a mark at the appropriate point on the line.
  
• This is an ordinal scale, but might appear to make it look like an interval scale.
  
• It is applied as faces scale such as feeling about their jobs.
  
• Example: rate your supervisor, excellent (10) – all right (5) – very bad (1).
  

Rating Scale Errors to Avoid

• Leniency
  
  • Negative Leniency
    
  • Positive Leniency
    
• Central Tendency
  
• Halo Effect
  

Ranking Scale

• They are used to tap preferences between two or among more objects or items (ordinal in nature).
  
• Such ranking may not give definitive clues to some of the answers sought, for example, the four product lines (35%, 25%, 20%, 20%).
  
• The methods used are the paired comparisons, forced choice, and the comparative scale.
  

Paired Comparison Scale

• The scale is used when, among a small number of objects, respondents are asked to choose between two objects at a time.
  
• The paired choices for n objects will be .
  
• The greater the number of objects or stimuli, the greater the number of paired comparisons presented to the respondents, and the greater the respondent fatigue.
  

Forced Choice Scale

• It enables respondents to rank objects relative to one another, among the alternatives provided.
  
• This is easier for the respondents.
  
• Example: assigning 1 for the most preferred choice and 5 for the least preferred for Fortune, Playboy, Time, People, and Prevention magazines.
  

Comparative Scale

• It provides a benchmark or a point of reference to assess attitude toward the current object, event, or situation under study.
  
• Example: volatile financial environment compared to stocks – invest in Treasury bonds (more useful, about the same, and less useful).
  

Summary of Scale

• Nominal data lend themselves to dichotomous or category scale.
  
• Ordinal data to any one of the ranking scales – paired comparison, forced choice, or comparative scales.
  
• Interval or interval-like data to the other rating scales such as Likert scale, itemized rating scale, fixed or constant sum rating scale, Stapel scale, graphic rating scale, consensus scale.
  

Summary of Scale (cont.)

• The semantic differential and the numerical scales are, strictly speaking, not interval scales, though they are often treated as such in data analysis.
  

Dimensions of a Scale

• Unidimensional
  
• Multidimensional
  

Scale Design Techniques

• Arbitrary scaling
  
• Consensus scaling
  
• Item Analysis scaling
  
• Cumulative scaling
  
• Factor scaling