CRC Research Methodology and Experimental Design 1 — Questions and Answers
Question 1: Which type of experimental design is most appropriate when a research chef wants to test the effect of three different hydrocolloids on gel strength while controlling for temperature and pH?
- Completely Randomized Design (CRD)
- Randomized Complete Block Design (RCBD)
- Factorial Design (Correct answer)
- Latin Square Design
Correct answer: Factorial Design
A factorial design allows simultaneous testing of multiple independent variables (hydrocolloid type, temperature, and pH) and their interactions on gel strength.
Question 2: In product development research, what is the primary purpose of a control sample?
- To act as the most expensive formulation for cost comparison
- To provide a baseline against which experimental samples are compared (Correct answer)
- To represent the competitor's product in blind testing
- To serve as the final prototype submitted for commercialization
Correct answer: To provide a baseline against which experimental samples are compared
A control sample establishes a baseline or reference point so that differences observed in experimental samples can be meaningfully attributed to the variable being tested.
Question 3: A research chef runs the same bench-top experiment five times under identical conditions to obtain five yield measurements. This practice improves which aspect of the study?
- Internal validity
- External validity
- Reliability (repeatability) (Correct answer)
- Construct validity
Correct answer: Reliability (repeatability)
Repeating the same experiment multiple times under identical conditions measures reliability/repeatability, confirming that results are consistent and not due to random error.
Question 4: Which statistical test is most commonly used to compare the means of three or more independent formulation groups in food product development?
- Paired t-test
- Chi-square test
- One-way ANOVA (Correct answer)
- Pearson correlation
Correct answer: One-way ANOVA
One-way ANOVA (Analysis of Variance) is the standard method for comparing means across three or more independent groups, determining if at least one group mean differs significantly.
Question 5: What does a p-value of 0.03 indicate in a food science experiment using a significance level of α = 0.05?
- There is a 3% probability the null hypothesis is true, so it is rejected
- The result is not statistically significant and the null hypothesis is retained
- The result is statistically significant and the null hypothesis is rejected (Correct answer)
- There is a 97% chance the experimental variable had no effect
Correct answer: The result is statistically significant and the null hypothesis is rejected
Because p = 0.03 is less than α = 0.05, the result is statistically significant, meaning you reject the null hypothesis and conclude the tested variable had a real effect.
Question 6: In a bench-to-pilot plant scale-up study, a research chef uses the same ingredient percentages but observes different texture outcomes. This discrepancy most likely reflects a failure in which research concept?
- Randomization
- Replication
- Scalability and process equivalence (Correct answer)
- Blinding
Correct answer: Scalability and process equivalence
Scalability and process equivalence ensure that unit operations (mixing, heating, cooling) translate proportionally from bench scale to pilot scale; differences in equipment dynamics often cause textural changes during scale-up.
Question 7: Which document formally outlines the objectives, scope, methodology, and success criteria for a food product development project before experimentation begins?
- Product specification sheet
- Bench record notebook
- Research protocol or project brief (Correct answer)
- HACCP plan
Correct answer: Research protocol or project brief
A research protocol or project brief establishes the objectives, scope, methods, and success criteria upfront, ensuring all stakeholders align before costly experimentation starts.
CRC Research Methodology and Experimental Design 1
Which type of experimental design is most appropriate when a research chef wants to test the effect of three different hydrocolloids on gel strength while controlling for temperature and pH?