CGM Data Collection & Analysis 2 — Questions and Answers
Question 1: Which sampling method divides a turf area into zones and randomly selects samples from each zone?
- Simple random sampling
- Stratified random sampling (Correct answer)
- Systematic sampling
- Convenience sampling
Correct answer: Stratified random sampling
Stratified random sampling divides the population into subgroups (strata) and samples randomly within each, improving representativeness.
Question 2: A grounds manager collects soil pH data over 5 years and notices a steady decline. This type of analysis is called:
- Regression analysis
- Trend analysis (Correct answer)
- Variance analysis
- Cluster analysis
Correct answer: Trend analysis
Trend analysis examines data over time to identify consistent patterns or directional changes in a variable.
Question 3: What does a high coefficient of variation (CV) in soil test results indicate?
- High data precision
- Low data variability
- High data variability relative to the mean (Correct answer)
- Strong correlation between variables
Correct answer: High data variability relative to the mean
A high CV indicates that the standard deviation is large relative to the mean, reflecting high variability in the dataset.
Question 4: Which data visualization tool is most appropriate for showing the frequency distribution of soil compaction readings?
- Pie chart
- Line graph
- Histogram (Correct answer)
- Scatter plot
Correct answer: Histogram
A histogram displays the frequency distribution of continuous data by grouping values into bins, ideal for compaction readings.
Question 5: When using a penetrometer to measure soil compaction, readings should be taken when soil moisture is:
- At field capacity (Correct answer)
- Bone dry
- Saturated
- Frozen
Correct answer: At field capacity
Penetrometer readings are most meaningful and comparable when soil is at field capacity, a standardized moisture condition.
Question 6: A grounds manager wants to determine if a new fertilizer treatment significantly improved turf quality scores. Which statistical test is most appropriate?
- Chi-square test
- t-test (Correct answer)
- Pearson correlation
- ANOVA with three groups
Correct answer: t-test
A t-test compares the means of two groups (treated vs. untreated) to determine if the difference is statistically significant.
Question 7: Which of the following best describes 'data normalization' in grounds management record-keeping?
- Deleting outlier data points
- Converting data to a common scale for comparison (Correct answer)
- Averaging all readings across a season
- Rounding values to the nearest whole number
Correct answer: Converting data to a common scale for comparison
Data normalization rescales data to a common range or scale, enabling valid comparisons between different measurement units or magnitudes.
CGM Data Collection & Analysis 2
Which sampling method divides a turf area into zones and randomly selects samples from each zone?