Topic 10: Measurement and Scaling

Question 1

What is measurement?

Answer 1

Process of describing some property of a phenomenon by assigning numbers in a reliable way

Question 2

How do you determine what needs to be measured to address a research question?

Answer 2

The problem definition process should determine which constructs/variables should be measured (Decision statement→Research questions→Hypotheses)

Question 3

How do you measure concepts?

Answer 3

You operationalize the variables (identify scales that correspond to variance in the concepts.
Variables are concepts who’s values can change and be measured

Question 4

What are constructs?

Answer 4

Concepts that can be measured in multiple ways with multiple variables

Question 5

What are the different levels of scale measurement?

Answer 5

• Nominal scale- assigns different arbitrary values to items purely to differentiate between them (Most elementary level of measurement, e.g: numbers of different race horses)
• Ordinal scale- assigns values to rank items in ascending or descending order (e.g: Top 5 horses in order of the place they finished)
• Interval scale- Have both nominal and ordinal quantities while also showing the amount of variance between different items (e.g: ranking the top 5 horses and showing what their race times where)
• Ratio scale- All the properties of interval scales and has a meaningful absolute zero value. (e.g: prices have an absolute zero, whereas temperature does not, 0 degrees does not equal the absence of heat)

Question 6

What are the 3 criteria for good measurement?

Answer 6

Reliability- how consistently does a measure provide the same results (assess reliability using the coefficient alpha method or the test-retest method)
Validity- a measures accuracy; extent to which a score truthfully represents a concept
Sensitivity- a measurement’s ability to accurately measure even small variance in results

Question 7

With regards to the requirements for good measurement

How is validity established?

Answer 7

• Construct validity (reliably measures and truthfully represents concept)
• Construct validity consists of:
• Face validity: results look realistic and appear at surface value to logically represent what was being measured
• Content validity: does the measure adequately cover the domain of interest (not more or less than what is being measured)
• Convergent validity: concepts that should correlate do in fact correlate
• Discriminant validity: how unique is the measure? A scale shouldn’t correlate too strongly with a measure of a different concept. (If they do, then one must ask whether they are actually different concepts or the same thing)

Question 8

What is an attitude?

Answer 8

How someone responds to aspects of the world (influenced by cognotive, affective (emotional/feeling) and behavioural components

Question 9

What are the techniques for measuring attitudes?

Answer 9

• Direct verbal statements used to measure behavioural intent (ranking, rating, sorting, choice)
• Qualitative techniques
• affective(emotional) components of attitudes can be measured using physiological measures (heart rate, pupil dilation)
• attitude rating scales

Question 10

What are the different types of rating scales and their characteristics?

Answer 10

• Category scale- indicate response from list of categories (easy to respond to, but lack of specific distinctions between options)
• Likert scale- scale of agreement/disagreement (easy to make, difficult to judge individual score meanings)
• Semantic differential & numerical scales- choose points on a scale inbetween 2 bipolar adjectives (easy to make, but bipolar adjectives must be found)
• Stapel scale- points on a scale with single adjective in the centre (don’t need bipolar adjectives, end points are numerical)
• Constant sum scale- divide total number among response alternatives (approximates interval measure, but complex to complete)
• Graphic scale- choose point on a continuum (visual impact, unlimited scale points, but no fixed answers)

Question 11

What are latent constructs and how would you represent them?

Answer 11

• Use of a likert scale that has multiple scale items to be rated
• After reverse coding if neccessary, all the respondent’s reactions are summed together to form a composite scale to represent all variables of the latent construct

Question 12

Questions to ask when selecting a measurement scale?

Answer 12

• Is ranking, sorting, rating or choice the best technique?
• Should a monadic(1 variable) or comparative scale(2 variables) be used?
• How many categories/response positions are needed to accurately measure an attitude?
• Balanced or unbalanced rating scale?
• Even or odd number of options?
• Should there be predetermined options to choose from?
• Single measure or index measure?