CSET Data Analysis & Reporting 4 — Questions and Answers
Question 1: A researcher finds a strong positive correlation (r = 0.85) between shoe size and reading ability in elementary school children. The best interpretation is:
- Larger shoe size causes better reading ability
- Better reading causes feet to grow
- A third variable (age) likely explains both (Correct answer)
- The correlation is too high to be valid
Correct answer: A third variable (age) likely explains both
Correlation does not imply causation; age is a confounding variable that influences both shoe size and reading ability.
Question 2: A teacher uses a rubric where different scorers give the same student essay very different scores. This assessment lacks:
- Content validity
- Inter-rater reliability (Correct answer)
- Construct validity
- Predictive validity
Correct answer: Inter-rater reliability
Inter-rater reliability refers to the consistency of scores assigned by different evaluators; inconsistent scores indicate low inter-rater reliability.
Question 3: A box-and-whisker plot shows the minimum, Q1, median, Q3, and maximum. The box itself represents:
- All the data values
- The range of the data
- The middle 50% of the data (Correct answer)
- Two standard deviations
Correct answer: The middle 50% of the data
The box in a box plot spans from Q1 to Q3, enclosing the interquartile range, which contains the middle 50% of values.
Question 4: Which sampling method involves randomly selecting intact groups rather than individual participants?
- Simple random sampling
- Stratified sampling
- Cluster sampling (Correct answer)
- Systematic sampling
Correct answer: Cluster sampling
Cluster sampling selects entire naturally occurring groups (like classrooms or schools) rather than choosing individuals one by one.
Question 5: A school district tracks the number of students qualifying for free or reduced lunch over five years. Which statistic would best show the year-to-year rate of change?
- Mean of the five years
- Percentage change from year to year (Correct answer)
- Total sum of all five years
- Standard deviation across years
Correct answer: Percentage change from year to year
Percentage change compares each year's value to the previous year's, directly showing the rate of change over time.
Question 6: A histogram with many bars of roughly equal height across the full range of values describes which type of distribution?
- Normal distribution
- Bimodal distribution
- Uniform distribution (Correct answer)
- Skewed distribution
Correct answer: Uniform distribution
A uniform distribution has approximately equal frequency across all value ranges, resulting in a flat histogram.
Question 7: When a test consistently measures what it is supposed to measure, it is said to have high:
- Reliability
- Validity (Correct answer)
- Difficulty
- Discrimination
Correct answer: Validity
Validity refers to the degree to which a test actually measures the construct or skill it is intended to measure.
CSET Data Analysis & Reporting 4
A researcher finds a strong positive correlation (r = 0.85) between shoe size and reading ability in elementary school children.
The best interpretation is: