CRC Research Methodology and Experimental Design 2 — Questions and Answers
Question 1: A research chef uses a 9-point hedonic scale to collect consumer preference data for a new sauce. What level of measurement does this scale represent?
- Nominal
- Ordinal
- Interval (Correct answer)
- Ratio
Correct answer: Interval
A 9-point hedonic scale is an interval scale because the distances between scale points are assumed equal, but it lacks a true zero point representing the complete absence of the attribute.
Question 2: What is the main advantage of using a blind experimental design in consumer taste testing?
- It reduces the number of samples needed for statistical significance
- It eliminates bias from brand expectations or prior product knowledge (Correct answer)
- It allows the researcher to skip randomization procedures
- It guarantees a larger and more diverse consumer panel
Correct answer: It eliminates bias from brand expectations or prior product knowledge
Blinding prevents panelists from knowing which sample is which brand or treatment, eliminating expectation bias and ensuring responses reflect only sensory perception.
Question 3: During iterative product development, a research chef documents every ingredient change, batch number, and observation in a bound notebook with dated entries. This practice supports which research principle?
- Randomization
- Traceability and reproducibility (Correct answer)
- Double-blinding
- Statistical power
Correct answer: Traceability and reproducibility
Meticulous, dated documentation in a laboratory notebook ensures traceability—any result can be traced back to exact conditions—and allows other researchers to reproduce the experiment.
Question 4: A research chef wants to determine whether there is a linear relationship between the concentration of a thickener (% w/w) and the resulting viscosity (cP). Which analytical approach is most appropriate?
- Chi-square test of independence
- Simple linear regression (Correct answer)
- One-way ANOVA
- Paired t-test
Correct answer: Simple linear regression
Simple linear regression models the relationship between one continuous predictor (thickener concentration) and one continuous outcome (viscosity), quantifying both the direction and strength of the linear relationship.
Question 5: In a designed experiment, which term describes the specific values or settings of the independent variable that are deliberately chosen for comparison?
- Replicates
- Confounders
- Treatment levels (Correct answer)
- Covariates
Correct answer: Treatment levels
Treatment levels are the specific values or categories of the independent variable set by the researcher—for example, 1%, 2%, and 3% salt concentrations in a brining study.
Question 6: A research team conducts a pilot plant trial and achieves results that match bench-scale findings. Later, the same protocol run in a commercial plant fails to replicate those results. This scenario best illustrates a problem with:
- Internal reliability
- Construct validity
- External validity and transferability (Correct answer)
- Statistical significance
Correct answer: External validity and transferability
External validity (transferability) refers to the extent that findings generalize to other settings; when results valid at pilot scale fail at commercial scale, external validity to that new environment is lacking.
Question 7: Which sampling strategy would a research chef use to ensure that consumer panel participants proportionally represent multiple demographic groups (age, gender, income) in a market study?
- Convenience sampling
- Snowball sampling
- Stratified random sampling (Correct answer)
- Systematic sampling
Correct answer: Stratified random sampling
Stratified random sampling divides the population into subgroups (strata) and randomly samples from each in proportion to its size, ensuring demographic representation in the panel.
CRC Research Methodology and Experimental Design 2
A research chef uses a 9-point hedonic scale to collect consumer preference data for a new sauce.
What level of measurement does this scale represent?